Group testing is a cost effective procedure for identifying defective items in a large population. It also improves the efficiency of the testing procedure when imperfect tests are employed.This study develops computational group-testing strategy based on Kline et. al.,(1989) testing strategy. Statistical moments based on this applied design have been generated. With advent of digital computers in 1980`s, group-testing strategy under discussion is handled in the context of computationa statistics.
Computational Pool-Testing with Retesting StrategyWaqas Tariq
Pool testing is a cost effective procedure for identifying defective items in a large population. It also improves the efficiency of the testing procedure when imperfect tests are employed. This study develops computational pool-testing strategy based on a proposed pool testing with re-testing strategy. Statistical moments based on this applied design have been generated. With advent of computers in 1980‘s, pool-testing with re-testing strategy under discussion is handled in the context of computational statistics. From this study, it has been established that re-testing reduces misclassifications significantly as compared to Dorfman procedure although re-testing comes with a cost i.e. increase in the number of tests. Re-testing considered improves the sensitivity and specificity of the testing scheme.
August 1, 2010. Design of Non-Randomized Medical Device Trials Based on Sub-Classification Using Propensity Score Quintiles, Topic Contributed Session on Medical Devices, (Greg Maislin and Donald B Rubin). Joint Statistical Meetings 2010, Vancouver Canada.
Hiv Replication Model for The Succeeding Period Of Viral Dynamic Studies In A...inventionjournals
International Journal of Mathematics and Statistics Invention (IJMSI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJMSI publishes research articles and reviews within the whole field Mathematics and Statistics, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online
This presentation is on using repeated measures design in the area of social sciences, behavioural sciences, management, sports, physical education etc.
PREDICTING CLASS-IMBALANCED BUSINESS RISK USING RESAMPLING, REGULARIZATION, A...IJMIT JOURNAL
We aim at developing and improving the imbalanced business risk modeling via jointly using proper
evaluation criteria, resampling, cross-validation, classifier regularization, and ensembling techniques.
Area Under the Receiver Operating Characteristic Curve (AUC of ROC) is used for model comparison
based on 10-fold cross validation. Two undersampling strategies including random undersampling (RUS)
and cluster centroid undersampling (CCUS), as well as two oversampling methods including random
oversampling (ROS) and Synthetic Minority Oversampling Technique (SMOTE), are applied. Three highly
interpretable classifiers, including logistic regression without regularization (LR), L1-regularized LR
(L1LR), and decision tree (DT) are implemented. Two ensembling techniques, including Bagging and
Boosting, are applied on the DT classifier for further model improvement. The results show that, Boosting
on DT by using the oversampled data containing 50% positives via SMOTE is the optimal model and it can
achieve AUC, recall, and F1 score valued 0.8633, 0.9260, and 0.8907, respectively.
Computational Pool-Testing with Retesting StrategyWaqas Tariq
Pool testing is a cost effective procedure for identifying defective items in a large population. It also improves the efficiency of the testing procedure when imperfect tests are employed. This study develops computational pool-testing strategy based on a proposed pool testing with re-testing strategy. Statistical moments based on this applied design have been generated. With advent of computers in 1980‘s, pool-testing with re-testing strategy under discussion is handled in the context of computational statistics. From this study, it has been established that re-testing reduces misclassifications significantly as compared to Dorfman procedure although re-testing comes with a cost i.e. increase in the number of tests. Re-testing considered improves the sensitivity and specificity of the testing scheme.
August 1, 2010. Design of Non-Randomized Medical Device Trials Based on Sub-Classification Using Propensity Score Quintiles, Topic Contributed Session on Medical Devices, (Greg Maislin and Donald B Rubin). Joint Statistical Meetings 2010, Vancouver Canada.
Hiv Replication Model for The Succeeding Period Of Viral Dynamic Studies In A...inventionjournals
International Journal of Mathematics and Statistics Invention (IJMSI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJMSI publishes research articles and reviews within the whole field Mathematics and Statistics, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online
This presentation is on using repeated measures design in the area of social sciences, behavioural sciences, management, sports, physical education etc.
PREDICTING CLASS-IMBALANCED BUSINESS RISK USING RESAMPLING, REGULARIZATION, A...IJMIT JOURNAL
We aim at developing and improving the imbalanced business risk modeling via jointly using proper
evaluation criteria, resampling, cross-validation, classifier regularization, and ensembling techniques.
Area Under the Receiver Operating Characteristic Curve (AUC of ROC) is used for model comparison
based on 10-fold cross validation. Two undersampling strategies including random undersampling (RUS)
and cluster centroid undersampling (CCUS), as well as two oversampling methods including random
oversampling (ROS) and Synthetic Minority Oversampling Technique (SMOTE), are applied. Three highly
interpretable classifiers, including logistic regression without regularization (LR), L1-regularized LR
(L1LR), and decision tree (DT) are implemented. Two ensembling techniques, including Bagging and
Boosting, are applied on the DT classifier for further model improvement. The results show that, Boosting
on DT by using the oversampled data containing 50% positives via SMOTE is the optimal model and it can
achieve AUC, recall, and F1 score valued 0.8633, 0.9260, and 0.8907, respectively.
The amount of information in the form of features and variables available to machine learning algorithms is ever increasing. This can lead to classifiers that are prone to overfitting in high dimensions, high dimensional models do not lend themselves to interpretable results, and the CPU and memory resources necessary to run on high-dimensional datasets severly limit the applications of the approaches.
Variable and feature selection aim to remedy this by finding a subset of features that in some way captures the information provided best.
In this paper we present the general methodology and highlight some specific approaches.
Statistical Prediction for analyzing Epidemiological Characteristics of COVID...Nuwan Sriyantha Bandara
In this presentation, we propose a novel integrated model for analyzing the characteristics of the epidemiological curve of COVID-19 by utilizing an enhanced compartmental statistical prediction model which is developed conferring susceptible-infectious susceptible (SIS) model, susceptible-infectious-removed (SIR) model, Dirichlet process model, and the interpretive structural model.
The oral presentation of the research has been presented at the International Research Conference 2020 of Sri Lanka Technological Campus on 17th June, 2020.
Abstract Link: http://repo.sltc.ac.lk/handle/1/82
This presentation discusses the application of discriminant analysis in sports research. One can understand the steps involved in the analysis and testing its assumptions.
INFLUENCE OF DATA GEOMETRY IN RANDOM SUBSET FEATURE SELECTIONIJDKP
The geometry of data, also known as probability distribution, is an important consideration for accurate computation of data mining tasks, such as pre-processing, classification and interpretation. The data geometry influences outcome and accuracy of the statistical analysis to a large extent. The current paper focuses on, understanding the influence of data geometry in the feature subset selection process using random forest algorithm. In practice, it is assumed that the data follows normal distribution and most of the time, it may not be true. The dimensionality reduction varies, due to change in the distribution of the data. A comparison is made using three standard distributions such as Triangular, Uniform and Normal Distribution. The results are discussed in this paper.
A New SDM Classifier Using Jaccard Mining Procedure (CASE STUDY: RHEUMATIC FE...Soaad Abd El-Badie
In this paper, a new Statistical Data Mining (SDM) technique is proposed using Jaccard Mining Procedure (JMP) contributing a novel classifier & predictor by applying very effective stages on the training and testing data depending on Jaccard (J) distance matrix Linked with the Gini Index Measure as precision measure for initiating a new classifier and a new predictor, The proposed SDM technique using JMP is applied and examined on a Rheumatic Fever Data to demonstrate its applicability.
A new sdm classifier using jaccard mining procedure case study rheumatic feve...ijbbjournal
In this paper, a new Statistical Data Mining (SDM) technique is proposed using Jaccard Mining Procedure
(JMP) contributing a novel classifier & predictor by applying very effective stages on the training data
depending on Jaccard (J) distance matrix Linked with the Gini Index Measure as precision measure for
initiating a new classifier and a new predictor, The proposed SDM technique using JMP is applied and
examined on a Rheumatic Fever Data to demonstrate its applicability.
A Mathematical Model for the Genetic Variation of Prolactin and Prolactin Rec...IJERA Editor
The Weibull distribution is a widely used model for studying fatigue and endurance life in engineering devices and materials. Recent advances in Weibull theory have also created numerous specialized Weibull applications. Modern computing technology has made many of these techniques accessible across the engineering spectrum. Despite its popularity, and wide applicability the traditional 2 – parameter and 3- parameter Weibull distribution is unable to capture all the lifetime phenomenon for instance the data set which has a non – monotonic failure rate function. Recently several generalization of Weibull distribution has been studied. An approach to the construction of flexible parametric model is to embed appropriate competing models into a larger model by adding shape parameter. Some recent generalizations of Weibull distribution including the Exponentiated Weibull, Extended Weibull, Modified Weibull are discussed and references [5] therein, along with their reliability functions. In this paper a new generalization of Weibull distribution called the transmuted Weibull distribution is utilized for our medical application. For example, Prolactin and prolactin receptors are present in normal breast tissue, benign breast disease, breast cancer cell lines, and breast tumour tissue, leading to speculation that the proliferative and antiapoptotic effects of prolactin in breast epithelial cells could be a factor in breast carcinogenesis. In this paper, a test for the distribution of prolactin concentrations in controls, by menopausal status and relationships with Serum Prolactin Levels and Breast Cancer Risk was investigated in the application part, by using Transmuted Weibull Distribution. As a result the mathematical curves for the Probability Density Function, Reliability Function and Hazard Rate Function are obtained for the corresponding medical curve given in the application part.
Personalisierung; der Schlüssel zum Erfolg in Q4 auf ShopwareNosto
Wie Sie das Einkaufserlebnis auf jeden Kunden individualisieren für ein erfolgreiches Q4.
Heute schauen wir uns an…
… wie Sie die Kundengewinnung durch gezielte Werbung und Aktionen stärken können
… wie Sie Konvertierungsraten und den AOV mit relevanten Produktempfehlungen steigern können
… wie Sie Kundenbindung mit personalisierter Kommunikation verbessern können
The amount of information in the form of features and variables available to machine learning algorithms is ever increasing. This can lead to classifiers that are prone to overfitting in high dimensions, high dimensional models do not lend themselves to interpretable results, and the CPU and memory resources necessary to run on high-dimensional datasets severly limit the applications of the approaches.
Variable and feature selection aim to remedy this by finding a subset of features that in some way captures the information provided best.
In this paper we present the general methodology and highlight some specific approaches.
Statistical Prediction for analyzing Epidemiological Characteristics of COVID...Nuwan Sriyantha Bandara
In this presentation, we propose a novel integrated model for analyzing the characteristics of the epidemiological curve of COVID-19 by utilizing an enhanced compartmental statistical prediction model which is developed conferring susceptible-infectious susceptible (SIS) model, susceptible-infectious-removed (SIR) model, Dirichlet process model, and the interpretive structural model.
The oral presentation of the research has been presented at the International Research Conference 2020 of Sri Lanka Technological Campus on 17th June, 2020.
Abstract Link: http://repo.sltc.ac.lk/handle/1/82
This presentation discusses the application of discriminant analysis in sports research. One can understand the steps involved in the analysis and testing its assumptions.
INFLUENCE OF DATA GEOMETRY IN RANDOM SUBSET FEATURE SELECTIONIJDKP
The geometry of data, also known as probability distribution, is an important consideration for accurate computation of data mining tasks, such as pre-processing, classification and interpretation. The data geometry influences outcome and accuracy of the statistical analysis to a large extent. The current paper focuses on, understanding the influence of data geometry in the feature subset selection process using random forest algorithm. In practice, it is assumed that the data follows normal distribution and most of the time, it may not be true. The dimensionality reduction varies, due to change in the distribution of the data. A comparison is made using three standard distributions such as Triangular, Uniform and Normal Distribution. The results are discussed in this paper.
A New SDM Classifier Using Jaccard Mining Procedure (CASE STUDY: RHEUMATIC FE...Soaad Abd El-Badie
In this paper, a new Statistical Data Mining (SDM) technique is proposed using Jaccard Mining Procedure (JMP) contributing a novel classifier & predictor by applying very effective stages on the training and testing data depending on Jaccard (J) distance matrix Linked with the Gini Index Measure as precision measure for initiating a new classifier and a new predictor, The proposed SDM technique using JMP is applied and examined on a Rheumatic Fever Data to demonstrate its applicability.
A new sdm classifier using jaccard mining procedure case study rheumatic feve...ijbbjournal
In this paper, a new Statistical Data Mining (SDM) technique is proposed using Jaccard Mining Procedure
(JMP) contributing a novel classifier & predictor by applying very effective stages on the training data
depending on Jaccard (J) distance matrix Linked with the Gini Index Measure as precision measure for
initiating a new classifier and a new predictor, The proposed SDM technique using JMP is applied and
examined on a Rheumatic Fever Data to demonstrate its applicability.
A Mathematical Model for the Genetic Variation of Prolactin and Prolactin Rec...IJERA Editor
The Weibull distribution is a widely used model for studying fatigue and endurance life in engineering devices and materials. Recent advances in Weibull theory have also created numerous specialized Weibull applications. Modern computing technology has made many of these techniques accessible across the engineering spectrum. Despite its popularity, and wide applicability the traditional 2 – parameter and 3- parameter Weibull distribution is unable to capture all the lifetime phenomenon for instance the data set which has a non – monotonic failure rate function. Recently several generalization of Weibull distribution has been studied. An approach to the construction of flexible parametric model is to embed appropriate competing models into a larger model by adding shape parameter. Some recent generalizations of Weibull distribution including the Exponentiated Weibull, Extended Weibull, Modified Weibull are discussed and references [5] therein, along with their reliability functions. In this paper a new generalization of Weibull distribution called the transmuted Weibull distribution is utilized for our medical application. For example, Prolactin and prolactin receptors are present in normal breast tissue, benign breast disease, breast cancer cell lines, and breast tumour tissue, leading to speculation that the proliferative and antiapoptotic effects of prolactin in breast epithelial cells could be a factor in breast carcinogenesis. In this paper, a test for the distribution of prolactin concentrations in controls, by menopausal status and relationships with Serum Prolactin Levels and Breast Cancer Risk was investigated in the application part, by using Transmuted Weibull Distribution. As a result the mathematical curves for the Probability Density Function, Reliability Function and Hazard Rate Function are obtained for the corresponding medical curve given in the application part.
Personalisierung; der Schlüssel zum Erfolg in Q4 auf ShopwareNosto
Wie Sie das Einkaufserlebnis auf jeden Kunden individualisieren für ein erfolgreiches Q4.
Heute schauen wir uns an…
… wie Sie die Kundengewinnung durch gezielte Werbung und Aktionen stärken können
… wie Sie Konvertierungsraten und den AOV mit relevanten Produktempfehlungen steigern können
… wie Sie Kundenbindung mit personalisierter Kommunikation verbessern können
The Garden Grocery: Food Safety and Selection at Farmers' Markets Alice Henneman
Farmers’ Markets offer a variety of fresh, locally-produced fruits, vegetables, bakery and meat products in a festive atmosphere. Get the most from your local Farmers’ Market with these tips for food safety, food selection and friendly advice for the Farmers' Market in your community!
Webinar: Excediendo las expectativas de tus clientes con PersonalizaciónNosto
Personalización no es un extra, sino un componente esencial en cualquier tienda online que quiera destacar sobre su competencia. La personalización, como estrategia esencial, tiene que ser aplicada en toda el funnel de compra - desde atraer nuevos visitantes, a convertir y retenerlos y finalmente aumentar el customer lifetime value.
Success Factors in Offset Deals: A Case Study Based ExaminationWaqas Tariq
The requests for offset obligations occurs primarily in the area of arms imports and covers the full range of industrial and commercial benefits that companies provide to foreign governments as inducements or conditions for the purchase of military goods and services. Increasingly, all major contracts ask for offset obligations. They are now key differentiators in major contracts and it is a fast growing market. For the suppliers, offsets are a key differentiator in earning new business and therefore should be accepted that much accurateness is put on the successful execution of the offset projects. Nevertheless, it comes to problems during the project phase and sometimes we’ve the situation that a offset project failed. The aim of this paper is to exam which success- giving factors are exists in the offset related interaction between buyer, seller and participating industry. The data for this investigation were obtained from secondary sources which were mainly accessible via internet. After data collection, an analysis was performed which was based on the context of this paper and also in connection with the chosen case study: Saudi Arabia. As a result of this analysis can be derived several success factors, which could be also seen as the foundation for an optimized execution of offset obligations. The paper concludes with a reflection of the investigation approach and as well with a classification of the subject offset. Furthermore the results of the analyzes are summarized and an outlook for further researches is given.
Impact of Solvency II yield curve extrapolation parameters on the valuation o...Thierry Moudiki
In order to price long term insurance guarantees, extrapolation of the yield curve is required. In this document, I present the method currently in use for Solvency II (presented in an article), and its impact on the valuation of an annuity.
You can play around with a web application explaining the impact of the extrapolation parameters, by typing the following commands in R:
# Loading Shiny package
library(shiny)
# Run the app in your browser; execs code from my Gist
runGist("ee4e7b9506a09e5d7cb8")
WÉBINAIRE : I’ultime guide de survie du eCommerce – Préparez-vous à conquérir...Nosto
Selon les informations que nous avons recueilli auprès des 13 000 boutiques en ligne qui utilisent Nosto, les marchands connaissent une baisse de revenu de 40 % entre le pic des ventes des fêtes de fin d'année et le mois de Janvier. En Février, les revenus sont 20 % inférieurs à la moyenne de l'année.
Dans ce wébinaire, notre spécialiste ecommerce vous présentera les problèmes les plus communs et les plus frustrants attendus pour le début d'année et vous conseillera sur les stratégies à adopter pour y faire face (tout cela à l'aide d'exemples en temps réel de la solution !). De plus, vous aurez l'occasion à la fin du wébinaire de poser vos questions à nos experts à propos de problèmes spécifiques rencontrés sur votre boutique ou dans votre secteur d'activité.
Voici comment tourner l'adversité en opportunité !
Computation of Moments in Group Testing with Re-testing and with Errors in In...CSCJournals
Screening of grouped urine sample was suggested during the Second World War as a method for reducing the cost of detecting syphilis in U.S. soldiers. Grouping has been used in epidemiological studies for screening of human immunodeficiency virus HIV/AIDS antibody to help curb the spread of the virus in recent studies. It reduces the cost of testing and more importantly it offers a feasible way to lower the misclassifications associated with labeling samples when imperfect tests are used. Furthermore, misclassifications can be reduced by employing a re-testing design in a group testing procedure. This study has developed a computational statistical model for classifying a large sample of interest based on a proposed design of group testing with re-testing. This model permits computation of moments on the number of tests and misclassification arising in this design. Simulated data from a multinomial distribution (specifically a trinomial distribution) has been used to illustrate these computations. From our study, it has been established that re-testing reduces misclassifications significantly and more so, it is stable at high rates of probability of incidences as compared to Dorfman procedure although re-testing comes with a cost i.e. increase in the number of tests. Re-testing considered reduces the sensitivity of the testing scheme but at the same time it improves the specificity.
PREDICTING CLASS-IMBALANCED BUSINESS RISK USING RESAMPLING, REGULARIZATION, A...IJMIT JOURNAL
We aim at developing and improving the imbalanced business risk modeling via jointly using proper evaluation criteria, resampling, cross-validation, classifier regularization, and ensembling techniques. Area Under the Receiver Operating Characteristic Curve (AUC of ROC) is used for model comparison based on 10-fold cross validation. Two undersampling strategies including random undersampling (RUS) and cluster centroid undersampling (CCUS), as well as two oversampling methods including random oversampling (ROS) and Synthetic Minority Oversampling Technique (SMOTE), are applied. Three highly interpretable classifiers, including logistic regression without regularization (LR), L1-regularized LR (L1LR), and decision tree (DT) are implemented. Two ensembling techniques, including Bagging and Boosting, are applied on the DT classifier for further model improvement. The results show that, Boosting on DT by using the oversampled data containing 50% positives via SMOTE is the optimal model and it can achieve AUC, recall, and F1 score valued 0.8633, 0.9260, and 0.8907, respectively.
12/24/16, 11(23 AMModule 8: Mastery Exercise | Schoology
Page 1 of 3https://app.schoology.com/assignment/885059160/assessment
Statistics and SPSS: WINTER16-B-8-MIS445-1
Module 8: Mastery Exercise
Question 1 (1 point)
In a body weight loss trial, the calculated F-value was 5.91 and the tabulated F (0.95, 3, 16) = 3.2; what should be the conclusion?
a Since F-calculated, 5.91 is bigger than F-tabulated, 3.2, therefore, reject the null hypothesis that dietary treatments were
similar in reducing body weight.
b Accept the null hypothesis of no dietary treatments effects.
c Nothing can be calculated.
Question 2 (1 point)
Some of the assumptions, for the data used in ANOVA are _________.
a data follows a normal distribution
b population means have similar variance (or standard deviation)
c samples are randomly selected and independent of one another
d all of the above
Question 3 (1 point)
Researchers wish to examine the effectiveness of a new weight-loss pill. A total of 200 obese adults are randomly assigned to one of
four conditions: weight-loss pill alone, weight-loss pill with a low-fat diet, placebo pill alone, or placebo pill with a low-fat diet. The
weight loss after six months of treatment is recorded in pounds for each subject. To analyze this data, you would use __________.
a a z-test
b a t-test
c an ANOVA F test
d a Chi-square test
Question 4 (1 point)
A medical research team is interested in determining whether a new drug has an effect on creatine kinase (CK), which is often assayed in
blood tests as an indicator of myocardial infarction. A random selection of 20 patients from a pool of possible subjects is selected, and
each subject is given the medication. The subjects’ CK levels are observed initially, after three (3) weeks, and again after six (6) weeks.
The purpose is to study the CK levels over time. Here is a summary of the findings:
Time (weeks) Mean CK level (U/L) Standard devia9on (U/L)
0 121 20.37
3 106 16.09
6 100 10.21
In this example, we notice that ____________.
a the data shows very strong evidence of a violation of the assumption that the three populations have the same standard
deviation
Questions 1-10 of 10 | Page 1 of 1
https://app.schoology.com/course/885058852
12/24/16, 11(23 AMModule 8: Mastery Exercise | Schoology
Page 2 of 3https://app.schoology.com/assignment/885059160/assessment
b ANOVA cannot be used on this data because the sample sizes are much too small
c the assumption that the data is independent for the three time points is unreasonable because the same subjects were
observed each time
d there is no reason not to use ANOVA in this situation
Question 5 (1 point)
The degree of freedom for the total number of observations in ANOVA will be ________.
a total number of observations less one
b total number of observations less two
c total number of observations plus one
d total number of observations plus two
Question 6 (1 point)
How much corn should be plante ...
1) The path length from A to B in the following graph is .docxmonicafrancis71118
1) The path length from A to B in the following graph is:
a- 2
b- 10
c- 22
d- There is no path
2) The minimum path weight from A to B in the following graph is:
a- 2
b- 10
c- 32
d- There is no path
3) The minimum path weight from A to E in the following graph is:
a- 1
b- 7
c- 67
d- There is no path
4) The longest cycle that starts at A and ends at A in the following graph is:
a- 104
b- 122
c- 42
d- There is no cycle
5) The entry AE in the length one adjacency matrix representation of the following graph is:
a- 7
b-
c- 0
d- None of the above
6) The entry AB in the length one adjacency matrix representation of the following graph is:
a- 10
b-
c- 22
d- 0
7) The entry AD in the length two adjacency matrix representation of the following graph is:
a- 60
b-
c- 44
d- 0
8) In the following graph, which of the following paths is considered a simple path?
a- AECAD
b- AEBFC
c- ADBFD
d- There is no simple path in the graph above
9) Some of the cliques the following graph has include: (A clique is a subgraph that is complete which means each node in the subgraph is connected to every other node n the subgraph). In the following graph, the subgraph AEBD is not a clique because A and B are not connected and E and D are not connected also, otherwise if they were connected it would be a clique.
a- ADBE, EBFC, EB, F, C
b- AEC, DBF
c- AEB, EBC
d- AECFBD
10) (TSP): Apply the nearest-neighbor algorithm to the complete weighted graph G in the following figure, beginning at vertex B, what is the path and the total weight?
a- BADECB with weight 725
b- BAEDCB with weight 775
c- TSP does not work with complete graph
d- None of the answers is true
Experimental Design 1
Running Head: EXPERIMENTAL DESIGN
Experimental Design and Some Threats to
Experimental Validity: A Primer
Susan Skidmore
Texas A&M University
Paper presented at the annual meeting of the Southwest Educational
Research Association, New Orleans, Louisiana, February 6, 2008.
Experimental Design 2
Abstract
Experimental designs are distinguished as the best method to respond to
questions involving causality. The purpose of the present paper is to explicate
the logic of experimental design and why it is so vital to questions that demand
causal conclusions. In addition, types of internal and external validity threats are
discussed. To emphasize the current interest in experimental designs, Evidence-
Based Practices (EBP) in medicine, psychology and education are highlighted.
Finally, cautionary statements regarding experimental designs are elucidated
with examples from the literature.
Experimental Design 3
The No Child Left Behind Act (NCLB) demands “scientifically based
research” as the basis for awarding many grants in education (2001).
Specifically, the 107th Congress (2001) delineated scientifically-based research
as that which “is evaluated using experimen.
CHAPTER 8 QUANTITATIVE METHODSWe turn now from the introductioJinElias52
CHAPTER 8 QUANTITATIVE METHODS
We turn now from the introduction, the purpose, and the questions and hypotheses to the method section of a proposal. This chapter presents essential steps in designing quantitative methods for a research proposal or study, with specific focus on survey and experimental designs. These designs reflect postpositivist philosophical assumptions, as discussed in Chapter 1. For example, determinism suggests that examining the relationships between and among variables is central to answering questions and hypotheses through surveys and experiments. In one case, a researcher might be interested in evaluating whether playing violent video games is associated with higher rates of playground aggression in kids, which is a correlational hypothesis that could be evaluated in a survey design. In another case, a researcher might be interested in evaluating whether violent video game playing causes aggressive behavior, which is a causal hypothesis that is best evaluated by a true experiment. In each case, these quantitative approaches focus on carefully measuring (or experimentally manipulating) a parsimonious set of variables to answer theory-guided research questions and hypotheses. In this chapter, the focus is on the essential components of a method section in proposals for a survey or experimental study.
DEFINING SURVEYS AND EXPERIMENTS
A survey design provides a quantitative description of trends, attitudes, and opinions of a population, or tests for associations among variables of a population, by studying a sample of that population. Survey designs help researchers answer three types of questions: (a) descriptive questions (e.g., What percentage of practicing nurses support the provision of hospital abortion services?); (b) questions about the relationships between variables (e.g., Is there a positive association between endorsement of hospital abortion services and support for implementing hospice care among nurses?); or in cases where a survey design is repeated over time in a longitudinal study; (c) questions about predictive relationships between variables over time (e.g., Does Time 1 endorsement of support for hospital abortion services predict greater Time 2 burnout in nurses?).
An experimental design systematically manipulates one or more variables in order to evaluate how this manipulation impacts an outcome (or outcomes) of interest. Importantly, an experiment isolates the effects of this manipulation by holding all other variables constant. When one group receives a treatment and the other group does not (which is a manipulated variable of interest), the experimenter can isolate whether the treatment and not other factors influence the outcome. For example, a sample of nurses could be randomly assigned to a 3-week expressive writing program (where they write about their deepest thoughts and feelings) or a matched 3-week control writing program (writing about the facts of their daily morning routine) to eval ...
Assignment 2 Tests of SignificanceThroughout this assignment yo.docxrock73
Assignment 2: Tests of Significance
Throughout this assignment you will review mock studies. You will needs to follow the directions outlined in the section using SPSS and decide whether there is significance between the variables. You will need to list the five steps of hypothesis testing (as covered in the lesson for Week 6) to see how every question should be formatted. You will complete all of the problems. Be sure to cut and past the appropriate test result boxes from SPSS under each problem and explain what you will do with your research hypotheses. All calculations should be coming from your SPSS. You will need to submit the SPSS output file to get credit for this assignment. This file will save as a .spv file and will need to be in a single file. In other words, you are not allowed to submit more than one output file for this assignment.
The five steps of hypothesis testing when using SPSS are as follows:
1. State your research hypothesis (H1) and null hypothesis (H0).
2. Identify your confidence interval (.05 or .01)
3. Conduct your analysis using SPSS.
4. Look for the valid score for comparison. This score is usually under ‘Sig 2-tail’ or ‘Sig. 2’. We will call this “p”.
5. Compare the two and apply the following rule:
a. If “p” is < or = confidence interval, than you reject the null.
Be sure to explain to the reader what this means in regards to your study. (Ex: will you recommend counseling services?)
* Be sure that your answers are clearly distinguishable. Perhaps you bold your font or use a different color.
ASSIGNMENT 2(200) WORD MINIUM
1. They allow us to see if our relationship is "statistically significant". (Remember that this only shows us that there is or is not a relationship but does NOT show us if it is big, small, or in-between.)
2. It let's us know if our findings can be generalized to the population which our sample was selected from and represents.
This week you will decide which test of significance you will use for your project. For this class your choices for tests will include one of the following:
· Chi-square
· t Test
· ANOVA
We will be using a process for hypothesis testing which outlines five steps researchers can follow to complete this process:
1. Write your research hypothesis (H1) and your null hypothesis (H0).
2. Identify and record your confidence interval. These are usually .05 (95%) or .01 (99%).
3. Complete the test using SPSS.
4. Identify the number under Sig. (2-tail). This will be represented by "p".
5. Compare the numbers in steps 2 and 4 and apply the following rule:
1. If p < or = confidence interval, than you reject the null hypothesis
Determine what to do with your null and explain this to your reader. Be sure to go beyond the phrase "reject or fail to reject the null" and explain how that impacts your research and best describes the relationship between variables.
TEST QUESTIONS-NEED FULL ANSWERS
Q1
Make up and discuss research examples corresponding to the various ...
Engineering Research Publication
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International Journal of Engineering & Technical Research
ISSN : 2321-0869 (O) 2454-4698 (P)
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The slides discuss comparing two means to ascertain which mean is of greater statistical significance. In these slides we will learn about three research questions in which the t-test can be used to analyze the data and compare the means from two independent groups, two paired samples, and a sample and a population.
WEEK 7 – EXERCISES Enter your answers in the spaces pr.docxwendolynhalbert
WEEK 7 – EXERCISES
Enter your answers in the spaces provided. Save the file using your last name as the beginning of the file name (e.g., ruf_week6_exercises) and submit via “Assignments.” When appropriate,
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. You can do the work by hand, scan/take a digital picture, and attach that file with your work.
A sports researcher gave a standard written test of eating habits to 12 randomly selected professionals, four each from baseball, football, and basketball. The results were as follows:
Eating Habits Scores
Baseball Players
Football Players
Basketball Players
34
27
35
18
28
44
21
67
47
65
42
61
Is there a difference in eating habits among professionals in the three sports? (Use the .05 significance level.)
a.
Use the five steps of hypothesis testing.
b.
Sketch the distribution involved.
c.
Determine effect size.
2.
To study the effectiveness of treatments for insomnia, a sleep researcher conducted a study with 12 participants.
Four participants were instructed to count sheep (Sheep Condition), four were told to concentrate on their breathing (Breathing Condition), and four were not given any special instructions. Over the next few days, measures were taken of how many minutes it took each participant to fall asleep. The average times for the participants in the Sheep Condition were 14, 28, 27, and 31; for those in the Breathing Condition, 25, 22, 17, and 14; and for those in the control condition, 45, 33, 30, and 41.
Do these results suggest that the different techniques have different effects?
(Use the .05 significance level.)
a.
Use the five steps of hypothesis testing.
b.
Sketch the distribution involved.
c.
Figure the effect size of the study.
d.
Explain your findings (including the logic of comparing within-group to between-group population variance estimates, how each of these is figured, and the
F
distribution).
High school juniors planning to attend college were randomly assigned to view one of four videos about a particular college, each differing according to what aspect of college life was emphasized: athletics, social life, scholarship, or artistic/cultural opportunities. After viewing the videos, the students took a test measuring their desire to attend this college. The results were as follows:
Desire to Attend this College
Athletics
Social Life
Scholarship
Art/Cultural
68
89
74
76
56
78
82
71
69
81
79
69
70
77
80
65
Do these results suggest that the type of activity emphasized in a college film affects desire to attend that college? (Use the .01 significance level.)
a.
Use the five steps of hypothesis testing.
b.
Sketch the distribution involved.
c.
Figure the effect size of the study.
d.
Explain the logic of what you have done to a person who is unfamiliar with the analysis of variance.
A team of psychologists designed a study in which 12 psychiatric patients diagnosed as having generalized anxiety disorder were randomly assigned to one of three new types of th.
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The Use of Java Swing’s Components to Develop a WidgetWaqas Tariq
Widget is a kind of application provides a single service such as a map, news feed, simple clock, battery-life indicators, etc. This kind of interactive software object has been developed to facilitate user interface (UI) design. A user interface (UI) function may be implemented using different widgets with the same function. In this article, we present the widget as a platform that is generally used in various applications, such as in desktop, web browser, and mobile phone. We also describe a visual menu of Java Swing’s components that will be used to establish widget. It will assume that we have successfully compiled and run a program that uses Swing components.
3D Human Hand Posture Reconstruction Using a Single 2D ImageWaqas Tariq
Passive sensing of the 3D geometric posture of the human hand has been studied extensively over the past decade. However, these research efforts have been hampered by the computational complexity caused by inverse kinematics and 3D reconstruction. In this paper, our objective focuses on 3D hand posture estimation based on a single 2D image with aim of robotic applications. We introduce the human hand model with 27 degrees of freedom (DOFs) and analyze some of its constraints to reduce the DOFs without any significant degradation of performance. A novel algorithm to estimate the 3D hand posture from eight 2D projected feature points is proposed. Experimental results using real images confirm that our algorithm gives good estimates of the 3D hand pose. Keywords: 3D hand posture estimation; Model-based approach; Gesture recognition; human- computer interface; machine vision.
Camera as Mouse and Keyboard for Handicap Person with Troubleshooting Ability...Waqas Tariq
Camera mouse has been widely used for handicap person to interact with computer. The utmost important of the use of camera mouse is must be able to replace all roles of typical mouse and keyboard. It must be able to provide all mouse click events and keyboard functions (include all shortcut keys) when it is used by handicap person. Also, the use of camera mouse must allow users troubleshooting by themselves. Moreover, it must be able to eliminate neck fatigue effect when it is used during long period. In this paper, we propose camera mouse system with timer as left click event and blinking as right click event. Also, we modify original screen keyboard layout by add two additional buttons (button “drag/ drop” is used to do drag and drop of mouse events and another button is used to call task manager (for troubleshooting)) and change behavior of CTRL, ALT, SHIFT, and CAPS LOCK keys in order to provide shortcut keys of keyboard. Also, we develop recovery method which allows users go from camera and then come back again in order to eliminate neck fatigue effect. The experiments which involve several users have been done in our laboratory. The results show that the use of our camera mouse able to allow users do typing, left and right click events, drag and drop events, and troubleshooting without hand. By implement this system, handicap person can use computer more comfortable and reduce the dryness of eyes.
A Proposed Web Accessibility Framework for the Arab DisabledWaqas Tariq
The Web is providing unprecedented access to information and interaction for people with disabilities. This paper presents a Web accessibility framework which offers the ease of the Web accessing for the disabled Arab users and facilitates their lifelong learning as well. The proposed framework system provides the disabled Arab user with an easy means of access using their mother language so they don’t have to overcome the barrier of learning the target-spoken language. This framework is based on analyzing the web page meta-language, extracting its content and reformulating it in a suitable format for the disabled users. The basic objective of this framework is supporting the equal rights of the Arab disabled people for their access to the education and training with non disabled people. Key Words : Arabic Moon code, Arabic Sign Language, Deaf, Deaf-blind, E-learning Interactivity, Moon code, Web accessibility , Web framework , Web System, WWW.
Real Time Blinking Detection Based on Gabor FilterWaqas Tariq
New method of blinking detection is proposed. The utmost important of blinking detections method is robust against different users, noise, and also change of eye shape. In this paper, we propose blinking detections method by measuring of distance between two arcs of eye (upper part and lower part). We detect eye arcs by apply Gabor filter onto eye image. As we know that Gabor filter has advantage on image processing application since it able to extract spatial localized spectral features, such line, arch, and other shape are more easily detected. After two of eye arcs are detected, we measure the distance between both by using connected labeling method. The open eye is marked by the distance between two arcs is more than threshold and otherwise, the closed eye is marked by the distance less than threshold. The experiment result shows that our proposed method robust enough against different users, noise, and eye shape changes with perfectly accuracy.
Computer Input with Human Eyes-Only Using Two Purkinje Images Which Works in ...Waqas Tariq
A method for computer input with human eyes-only using two Purkinje images which works in a real time basis without calibration is proposed. Experimental results shows that cornea curvature can be estimated by using two light sources derived Purkinje images so that no calibration for reducing person-to-person difference of cornea curvature. It is found that the proposed system allows usersf movements of 30 degrees in roll direction and 15 degrees in pitch direction utilizing detected face attitude which is derived from the face plane consisting three feature points on the face, two eyes and nose or mouth. Also it is found that the proposed system does work in a real time basis.
Toward a More Robust Usability concept with Perceived Enjoyment in the contex...Waqas Tariq
Mobile multimedia service is relatively new but has quickly dominated people¡¯s lives, especially among young people. To explain this popularity, this study applies and modifies the Technology Acceptance Model (TAM) to propose a research model and conduct an empirical study. The goal of study is to examine the role of Perceived Enjoyment (PE) and what determinants can contribute to PE in the context of using mobile multimedia service. The result indicates that PE is influencing on Perceived Usefulness (PU) and Perceived Ease of Use (PEOU) and directly Behavior Intention (BI). Aesthetics and flow are key determinants to explain Perceived Enjoyment (PE) in mobile multimedia usage.
Collaborative Learning of Organisational KnolwedgeWaqas Tariq
This paper presents recent research into methods used in Australian Indigenous Knowledge sharing and looks at how these can support the creation of suitable collaborative envi- ronments for timely organisational learning. The protocols and practices as used today and in the past by Indigenous communities are presented and discussed in relation to their relevance to a personalised system of knowledge sharing in modern organisational cultures. This research focuses on user models, knowledge acquisition and integration of data for constructivist learning in a networked repository of or- ganisational knowledge. The data collected in the repository is searched to provide collections of up-to-date and relevant material for training in a work environment. The aim is to improve knowledge collection and sharing in a team envi- ronment. This knowledge can then be collated into a story or workflow that represents the present knowledge in the organisation.
Our research aims to propose a global approach for specification, design and verification of context awareness Human Computer Interface (HCI). This is a Model Based Design approach (MBD). This methodology describes the ubiquitous environment by ontologies. OWL is the standard used for this purpose. The specification and modeling of Human-Computer Interaction are based on Petri nets (PN). This raises the question of representation of Petri nets with XML. We use for this purpose, the standard of modeling PNML. In this paper, we propose an extension of this standard for specification, generation and verification of HCI. This extension is a methodological approach for the construction of PNML with Petri nets. The design principle uses the concept of composition of elementary structures of Petri nets as PNML Modular. The objective is to obtain a valid interface through verification of properties of elementary Petri nets represented with PNML.
Development of Sign Signal Translation System Based on Altera’s FPGA DE2 BoardWaqas Tariq
The main aim of this paper is to build a system that is capable of detecting and recognizing the hand gesture in an image captured by using a camera. The system is built based on Altera’s FPGA DE2 board, which contains a Nios II soft core processor. Image processing techniques and a simple but effective algorithm are implemented to achieve this purpose. Image processing techniques are used to smooth the image in order to ease the subsequent processes in translating the hand sign signal. The algorithm is built for translating the numerical hand sign signal and the result are displayed on the seven segment display. Altera’s Quartus II, SOPC Builder and Nios II EDS software are used to construct the system. By using SOPC Builder, the related components on the DE2 board can be interconnected easily and orderly compared to traditional method that requires lengthy source code and time consuming. Quartus II is used to compile and download the design to the DE2 board. Then, under Nios II EDS, C programming language is used to code the hand sign translation algorithm. Being able to recognize the hand sign signal from images can helps human in controlling a robot and other applications which require only a simple set of instructions provided a CMOS sensor is included in the system.
An overview on Advanced Research Works on Brain-Computer InterfaceWaqas Tariq
A brain–computer interface (BCI) is a proficient result in the research field of human- computer synergy, where direct articulation between brain and an external device occurs resulting in augmenting, assisting and repairing human cognitive. Advanced works like generating brain-computer interface switch technologies for intermittent (or asynchronous) control in natural environments or developing brain-computer interface by Fuzzy logic Systems or by implementing wavelet theory to drive its efficacies are still going on and some useful results has also been found out. The requirements to develop this brain machine interface is also growing day by day i.e. like neuropsychological rehabilitation, emotion control, etc. An overview on the control theory and some advanced works on the field of brain machine interface are shown in this paper.
Exploring the Relationship Between Mobile Phone and Senior Citizens: A Malays...Waqas Tariq
There is growing ageing phenomena with the rise of ageing population throughout the world. According to the World Health Organization (2002), the growing ageing population indicates 694 million, or 223% is expected for people aged 60 and over, since 1970 and 2025.The growth is especially significant in some advanced countries such as North America, Japan, Italy, Germany, United Kingdom and so forth. This growing older adult population has significantly impact the social-culture, lifestyle, healthcare system, economy, infrastructure and government policy of a nation. However, there are limited research studies on the perception and usage of a mobile phone and its service for senior citizens in a developing nation like Malaysia. This paper explores the relationship between mobile phones and senior citizens in Malaysia from the perspective of a developing country. We conducted an exploratory study using contextual interviews with 5 senior citizens of how they perceive their mobile phones. This paper reveals 4 interesting themes from this preliminary study, in addition to the findings of the desirable mobile requirements for local senior citizens with respect of health, safety and communication purposes. The findings of this study bring interesting insight to local telecommunication industries as a whole, and will also serve as groundwork for more in-depth study in the future.
Principles of Good Screen Design in WebsitesWaqas Tariq
Visual techniques for proper arrangement of the elements on the user screen have helped the designers to make the screen look good and attractive. Several visual techniques emphasize the arrangement and ordering of the screen elements based on particular criteria for best appearance of the screen. This paper investigates few significant visual techniques in various web user interfaces and showcases the results for better understanding and their presence.
Virtual teams are used more and more by companies and other organizations to receive benefits. They are a great way to enable teamwork in situations where people are not sitting in the same physical place at the same time. As companies seek to increase the use of virtual teams, a need exists to explore the context of these teams, the virtuality of a team and software that may help these teams working virtualy. Virtual teams have the same basic principles as traditional teams, but there is one big difference. This difference is the way the team members communicate. Instead of using the dynamics of in-office face-to-face exchange, they now rely on special communication channels enabled by modern technologies, such as e-mails, faxes, phone calls and teleconferences, virtual meetings etc. This is why this paper is focused on the issues regarding virtual teams, and how these teams are created and progressing in Albania.
Cognitive Approach Towards the Maintenance of Web-Sites Through Quality Evalu...Waqas Tariq
It is a well established fact that the Web-Applications require frequent maintenance because of cutting– edge business competitions. The authors have worked on quality evaluation of web-site of Indian ecommerce domain. As a result of that work they have made a quality-wise ranking of these sites. According to their work and also the survey done by various other groups Futurebazaar web-site is considered to be one of the best Indian e-shopping sites. In this research paper the authors are assessing the maintenance of the same site by incorporating the problems incurred during this evaluation. This exercise gives a real world maintainability problem of web-sites. This work will give a clear picture of all the quality metrics which are directly or indirectly related with the maintainability of the web-site.
USEFul: A Framework to Mainstream Web Site Usability through Automated Evalua...Waqas Tariq
A paradox has been observed whereby web site usability is proven to be an essential element in a web site, yet at the same time there exist an abundance of web pages with poor usability. This discrepancy is the result of limitations that are currently preventing web developers in the commercial sector from producing usable web sites. In this paper we propose a framework whose objective is to alleviate this problem by automating certain aspects of the usability evaluation process. Mainstreaming comes as a result of automation, therefore enabling a non-expert in the field of usability to conduct the evaluation. This results in reducing the costs associated with such evaluation. Additionally, the framework allows the flexibility of adding, modifying or deleting guidelines without altering the code that references them since the guidelines and the code are two separate components. A comparison of the evaluation results carried out using the framework against published evaluations of web sites carried out by web site usability professionals reveals that the framework is able to automatically identify the majority of usability violations. Due to the consistency with which it evaluates, it identified additional guideline-related violations that were not identified by the human evaluators.
Robot Arm Utilized Having Meal Support System Based on Computer Input by Huma...Waqas Tariq
A robot arm utilized having meal support system based on computer input by human eyes only is proposed. The proposed system is developed for handicap/disabled persons as well as elderly persons and tested with able persons with several shapes and size of eyes under a variety of illumination conditions. The test results with normal persons show the proposed system does work well for selection of the desired foods and for retrieve the foods as appropriate as usersf requirements. It is found that the proposed system is 21% much faster than the manually controlled robotics.
Dynamic Construction of Telugu Speech Corpus for Voice Enabled Text EditorWaqas Tariq
In recent decades speech interactive systems have gained increasing importance. Performance of an ASR system mainly depends on the availability of large corpus of speech. The conventional method of building a large vocabulary speech recognizer for any language uses a top-down approach to speech. This approach requires large speech corpus with sentence or phoneme level transcription of the speech utterances. The transcriptions must also include different speech order so that the recognizer can build models for all the sounds present. But, for Telugu language, because of its complex nature, a very large, well annotated speech database is very difficult to build. It is very difficult, if not impossible, to cover all the words of any Indian language, where each word may have thousands and millions of word forms. A significant part of grammar that is handled by syntax in English (and other similar languages) is handled within morphology in Telugu. Phrases including several words (that is, tokens) in English would be mapped on to a single word in Telugu.Telugu language is phonetic in nature in addition to rich in morphology. That is why the speech technology developed for English cannot be applied to Telugu language. This paper highlights the work carried out in an attempt to build a voice enabled text editor with capability of automatic term suggestion. Main claim of the paper is the recognition enhancement process developed by us for suitability of highly inflecting, rich morphological languages. This method results in increased speech recognition accuracy with very much reduction in corpus size. It also adapts Telugu words to the database dynamically, resulting in growth of the corpus.
An Improved Approach for Word Ambiguity RemovalWaqas Tariq
Word ambiguity removal is a task of removing ambiguity from a word, i.e. correct sense of word is identified from ambiguous sentences. This paper describes a model that uses Part of Speech tagger and three categories for word sense disambiguation (WSD). Human Computer Interaction is very needful to improve interactions between users and computers. For this, the Supervised and Unsupervised methods are combined. The WSD algorithm is used to find the efficient and accurate sense of a word based on domain information. The accuracy of this work is evaluated with the aim of finding best suitable domain of word. Keywords: Human Computer Interaction, Supervised Training, Unsupervised Learning, Word Ambiguity, Word sense disambiguation
Parameters Optimization for Improving ASR Performance in Adverse Real World N...Waqas Tariq
From the existing research it has been observed that many techniques and methodologies are available for performing every step of Automatic Speech Recognition (ASR) system, but the performance (Minimization of Word Error Recognition-WER and Maximization of Word Accuracy Rate- WAR) of the methodology is not dependent on the only technique applied in that method. The research work indicates that, performance mainly depends on the category of the noise, the level of the noise and the variable size of the window, frame, frame overlap etc is considered in the existing methods. The main aim of the work presented in this paper is to use variable size of parameters like window size, frame size and frame overlap percentage to observe the performance of algorithms for various categories of noise with different levels and also train the system for all size of parameters and category of real world noisy environment to improve the performance of the speech recognition system. This paper presents the results of Signal-to-Noise Ratio (SNR) and Accuracy test by applying variable size of parameters. It is observed that, it is really very hard to evaluate test results and decide parameter size for ASR performance improvement for its resultant optimization. Hence, this study further suggests the feasible and optimum parameter size using Fuzzy Inference System (FIS) for enhancing resultant accuracy in adverse real world noisy environmental conditions. This work will be helpful to give discriminative training of ubiquitous ASR system for better Human Computer Interaction (HCI). Keywords: ASR Performance, ASR Parameters Optimization, Multi-Environmental Training, Fuzzy Inference System for ASR, ubiquitous ASR system, Human Computer Interaction (HCI)
How to Create Map Views in the Odoo 17 ERPCeline George
The map views are useful for providing a geographical representation of data. They allow users to visualize and analyze the data in a more intuitive manner.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
How to Split Bills in the Odoo 17 POS ModuleCeline George
Bills have a main role in point of sale procedure. It will help to track sales, handling payments and giving receipts to customers. Bill splitting also has an important role in POS. For example, If some friends come together for dinner and if they want to divide the bill then it is possible by POS bill splitting. This slide will show how to split bills in odoo 17 POS.
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
We all have good and bad thoughts from time to time and situation to situation. We are bombarded daily with spiraling thoughts(both negative and positive) creating all-consuming feel , making us difficult to manage with associated suffering. Good thoughts are like our Mob Signal (Positive thought) amidst noise(negative thought) in the atmosphere. Negative thoughts like noise outweigh positive thoughts. These thoughts often create unwanted confusion, trouble, stress and frustration in our mind as well as chaos in our physical world. Negative thoughts are also known as “distorted thinking”.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Ethnobotany and Ethnopharmacology:
Ethnobotany in herbal drug evaluation,
Impact of Ethnobotany in traditional medicine,
New development in herbals,
Bio-prospecting tools for drug discovery,
Role of Ethnopharmacology in drug evaluation,
Reverse Pharmacology.
The Indian economy is classified into different sectors to simplify the analysis and understanding of economic activities. For Class 10, it's essential to grasp the sectors of the Indian economy, understand their characteristics, and recognize their importance. This guide will provide detailed notes on the Sectors of the Indian Economy Class 10, using specific long-tail keywords to enhance comprehension.
For more information, visit-www.vavaclasses.com
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
ESC Beyond Borders _From EU to You_ InfoPack general.pdf
Group Testing with Test Errors Made Easier
1. Nyongesa L.Kennedy & Syaywa J.Paul
International Journal of Scientific and Statistical Computing (IJSSC), Volume (1): Issue (1) 1
Group Testing With Test Errors Made Easier
Nyongesa L. Kennedy knyongesa@hotmail.com
Department of Mathematics,
Masinde Muliro University of Science and Technology,
190 kakamega, Kenya
Paul J. Syaywa syaywa@yahoo.com
Department of Mathematics
Masinde Muliro University of Science and Technology,
190 kakamega, Kenya
Research Partially Supported by MMUST-URF
Abstract
Group testing is a cost-effective procedure for identifying defective items in a
large population. It also improves the efficiency of the testing procedure when
imperfect tests are employed. This study develops computational group-testing
strategy based on [5] testing strategy. Statistical moments based on this applied
design have been generated. With advent of digital computers in 1980‘s, group-
testing strategy under discussion is handled in the context of computational
statistics.
Keywords: False-negative; False-positive; Group; Imperfect-tests; Pool.
1. INTRODUCTION
Sequential testing of a population in the form of grouped sample started the way back in the
second world war by [2] as a cost-effective method for screening syphilis in US soldiers returning
from abroad. The [2] idea entails putting together individuals to form a group, and then testing the
group rather than testing each individual for evidence or absence of the characteristic of interest.
Epidemiological studies that use group testing have one of the two objectives. The first objective
is to screen a large population with a view to identifying those individuals with a trait (cf. [2]). The
second objective is to estimate the rate of the trait (cf. [10] and [9]). For either objective, group
testing is more cost effective than individual testing especially when the rate of the trait is low
because if a group tests negative it implies that none of the individuals that constitute the
group have the trait, and thus it is not necessary to test each individual in the group.
In recent years, there has been renewed interest in group testing strategies of biological
specimens because of the application in HIV/Aids epidemiology (cf. [5]). The procedure has
potential in the application of HIV/Aids testing because disease prevalence is estimated without
necessarily identifying the subject (cf. [3]). [12] studied the cost-effectiveness of pooling algorithm
2. Nyongesa L.Kennedy & Syaywa J.Paul
International Journal of Scientific and Statistical Computing (IJSSC), Volume (1): Issue (1) 2
for the first objective of identifying individuals with the trait. In their procedure, each individual
group that test positive is divided into two equal groups, which are then tested. Groups that tested
positive were further sub-divided and tested and so on. [13] extended this work by considering
pooling algorithms when there are errors and showed that some of these algorithms can reduce
the error rates of the screening procedures (the false positives and false negatives) compared to
individual testing. [7] examined group testing with re-testing and observed that re-test improves
the sensitivity and specificity of the group-testing algorithm.
Recent studies have focused on the second objective of estimating the rate of the trait using
group-testing strategy. [11] discussed the procedure as a potential method for use by
pharmaceutical companies in discovering drugs in the early stages. [8] has proposed an
estimator in pool testing strategy that benefit from re-testing the pools. He observed that re-
testing improves the efficiency of the estimator.
In this study, we discuss the computation of statistical measures in pool testing strategy with
imperfect test via computer package MATLAB based on [5] design of pool testing strategy. To the
authors knowledge no article has appeared in the literature of group-testing as championed by [2]
that has discussed the procedure in computational aspect. The rest of the paper is arranged as
follows: Group testing strategy with imperfect test or in the presence of test errors is introduced in
Section 2. Various statistical moments are generated in Section 3. Misclassification in the
proposed algorithm as a result of test errors is discussed in Section 4.Section 5 provides the
conclusion to the present study.
2. THE TESTING STRATEGY
In this study, we generalize the group testing strategy by introducing the error component in the
testing scheme so that the earlier proposed strategies become special cases as proposed by [5].
The strategy proposed in this study is as follows. Initially, group the population under investigation
into a single group of size n and carry out a test on the group. If the test result is negative, further
testing is discontinued. If the test result is positive, the group is divided into groups of equal sizes
(nk), and each group is subjected to group-testing. If the group tests positive, individual testing is
carried out. Diagrammatic description of the procedure has been presented in Figure 1.
FIGURE 1: Block Testing Strategy
nb21 ……………………i
_
+
…….………………1 2 i
Positive result on the test
Negative result on the test
3. Nyongesa L.Kennedy & Syaywa J.Paul
International Journal of Scientific and Statistical Computing (IJSSC), Volume (1): Issue (1) 3
3. MOMENTS IN THE GROUP TESTING STRATEGY
Generation of random numbers from distributions form a basis for generation of moments in this
section. Notice that, in order to use a computer to initiate a simulation study, we must be able to
generate the values of a uniform (0,1) random variables; such variates are called random
numbers, most computers have in-built subroutines, called a random number generator. For
further discussion on this subject see [6].With the above in mind, we are in a position to generate
moment measures in our proposed group testing strategy. In our testing strategy, we shall
assume that tests under use are imperfect so that when tests are assumed to be perfect would be
a special case. Before the generation of moments, we shall require the composite probability of
classifying a group as positive, denoted by π and given by
(1)
where k is the group size, p is the probably of incidence, and are the sensitivity and
specificity of the test in use, respectively. Equation (1) is easily derived by the law of total
probability. In our study, (1) is the probability of success. Therefore, we shall generate random
numbers from a binomial distribution with probability of success . Now, with (1) at hand, to
convert the data set {xi} generated from U (0, 1) into zeros and ones, we use the indicator
function
But from (1), it is clear that since (0, 1) and and .
Also, notice that in situations where the test kits are perfect, . Then (1)
reduces to
(2)
and if the group size is one, i.e., k = 1, (1) reduces to
(3)
Let X denote the number of defective groups (groups that test positive on the test), then X ~
binomial(n, π ). Hence, various statistical measures; mean, standard deviation, Kurtosis and
skewness have been computed by the aid of statistical packages. In addition, the total numbers
of tests, cost, and relative savings have been computed. We utilize Equations (1) and (3) to
generate these moments as presented in Tables 1a (i), 1a(ii), 1a (iii), though 2(b). Graphical
presentations are provided in Figures2(a) through 2(c) in the Appendix.
The simulation at population size 100 with groups of size 10 when the sensitivity and specificity of
the tests in use are 99% is provided in Table 1(a)(i). It can be observed from the simulated results
that:
4. Nyongesa L.Kennedy & Syaywa J.Paul
International Journal of Scientific and Statistical Computing (IJSSC), Volume (1): Issue (1) 4
• The numbers of defectives increase with increase in the incidence probability p
• The number of tests increases with increase in p,
• Relative savings decrease with increase is p.
If the population size is increased to 500 or 1000 from 100 with group size 20, as presented in
Tables 1a(ii) and 1a(iii), respectively, similar observations are made as noted above. Further,
notice that when the population size is fixed but the group size is increased, more defectives are
realized but there is no significant difference in relative savings. This is noted when we compare
Table 1a(ii) and Table 1a(iii).
Now, varying the sensitively and specificity from 99% to 95% as provided by Tables 1 b(i) to 1
b(iii), we draw similar conclusion. Graphical evidence of the observations on average number of
tests required to identify all defective items in the group is provided by Figures 2(a) through 2(c).
Clearly, the observations made are true in practice. Group testing strategy is only visible when
the incidents probability is small [2]. Otherwise individual testing is preferred. Thus, the tables
provides empirical evidence of the group testing scheme.
4. MISCLASSIFICATIONS IN GROUP TESTING STRATEGY
Our main assumption in the discussion of this study was that test act independently and errors
are part of the design as it is the case in practice ([7],[1]). Thus, misclassifications are bound to
arise in the testing scheme. There are two possible misclassifications in the literature of group-
testing namely:
• A defective item is classified as non-defective and termed as false negative,
• A non-defective item classified as defective, false positive.
The probabilities of interest here are the probability of false positive
and the probability of false negative is
We now utilize (4) and (5) to compute misclassifications as presented in Tables 3(a), 3(b),3(c),
and 3(d). The simulated results are also presented graphically in Figures 3(a), 3(b), 3(c) and 3(d).
Computed values of false positives for group sizes:100, 500, 1000 with group sizes of 10, 20, and
50 have been presented in Table 3(a) and 3(b), when tests with equal sensitively and specificity
are employed. It can be observed that:
• The number of false positive increases with increase in p,
• More false positives are realized with increase in group size. In fact, when the group size is
5. Nyongesa L.Kennedy & Syaywa J.Paul
International Journal of Scientific and Statistical Computing (IJSSC), Volume (1): Issue (1) 5
doubled,
false positive increase by at least two fold,
• Increase in the efficiency of the test kits results into a reduction in false positives.
From Tables 3(c) and 3(d), we observe that:
• The number of false-negative increase at a slow rate with increase in the incidence probability,
• The number of false negatives approximately doubles when the group size is doubled,
• If the efficiency of the tests is increased, fewer false negatives are realized.
5. CONCLUSION
We have presented a computational pool testing strategy with test errors based on [5] design. It is
evident from the computed results; Tables 1 (a)I to 1 (a) iii, that groups should be relatively small
to be able to obtain the desired results as relative savings decrease with increase in pool sizes.
This observation is feasible in situations where dilution effect can affect the results (cf. [4]). Also
notice that relative savings is prominent when the efficiency of the test kits are high. Furthermore,
the computed results support the idea that the procedure is only feasible when the prevalence
rate is small otherwise individual testing is preferable. i.e relative savings decrease with increase
in prevalence rate. Misclassifications are prominent when the efficiency of the test kits are low
and incidence probability high, calling for re-testing, [7] and [8].
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