Ppt research Methods and statistical consultancy

By: Tilaye M. (Bsc, MSc in biostatistics ): gc2003@ymail.com
Wollo University, College of Science, Department of Statistics
Dessie, Ethiopia
October, 2017
1
Research Methods and statistical consultancy (stat3151)
for graduating class statistics students !

Outline of the course
WU,Department of Statistics2
This course will focus on:-
 Definition and types of research
 Motivation and Objectives of research
 Identification of research problem
Content and ways of research report
 research proposal development and
Concepts of Statistical consultancy

Introduction
 important question to be raised to conduct a research
What is Research?
What are research types ?
What are motivation of for research?
How we identify research problem?

Definition of research
Research is a search for acquiring knowledge.
 The Advanced Learner’s Dictionary of
Current English lays down the meaning of
research as “a careful investigation or
inquiry especially through search for new
facts in any branch of knowledge.”

Different scholars define research in
different ways:
1. Redman and Mory:- define research as a “systematized
effort to gain new knowledge.”
 Some people consider research as a movement :-A movement
from the known to the unknown.
2. Research is, thus, an original contribution to the existing
stock of knowledge making for its advancement.
3. Research is the systematic collection, analysis and
interpretation of data to answer a certain question or
solve a problem.

Cont…
 „research‟ refers to
 the systematic method consisting of enunciating
 the problem,
 formulating a hypothesis,
 collecting the facts or data, analyzing the facts and reaching
 certain conclusions either
 in the form of solutions(s) towards the concerned problem or
 in certain generalizations for some theoretical formulation.

Cont..
 It is also a scientific investigation that provides the basis for nearly
all government policies in our economic system.
 Through research we can develop alternative policies and can as
well examine the consequences of each of these alternatives.
 Therefore, research is investigation of new facts or alternatives
through searching new knowledge.

In general, the following characteristics may be gathered
from the definitions of ‘Research’ from different scholars.
1. It gathers new knowledge or data from primary or first-hand sources.
2. It places emphasis upon the discovery of general principles.
3. It is an exact systematic and accurate investigation.
4. It uses certain valid data gathering devices.
5. It is logical and objective.
6. The researcher resists the temptation to seek only the data that support his
hypotheses.
7. The researcher eliminates personal feelings and preferences.
8. It endeavours to organise data in quantitative terms.
9. Research is patient and unhurried activity.
10. The researcher is willing to follow his procedures to the conclusions that
may be unpopular and bring social disapproval.
11. Research is carefully recorded and reported.
12. Conclusions and generalizations are arrived at carefully and cautiously.

RESEARCH OBJECTIVES!
 The purpose of research is
 to discover answers to questions through the application of
scientific procedures.
 In research you find out the truth which is hidden and which has
not been discovered as yet.
 So research has its own specific objectives for which investigation
can be made.

Research objectives as falling into a
number of following broad groupings:
1. To gain familiarity with a phenomenon or to achieve
new insights into it (exploratory or formulative
research studies);
2. To portray accurately the characteristics of a
particular individual, situation or a group
(descriptive research studies);
3. To determine the frequency with which something
occurs or with which it is associated with something
else (diagnostic research studies);
4. To test a hypothesis of a causal relationship between
variables (hypothesis-testing research studies).

What are the motivation in research?
The possible motives for doing research may
be either one or more of the following:
1. Desire to get a research degree along with its
consequential benefits;
2. Desire to face the challenge in solving the unsolved
problems, i.e., concern over practical problems
initiates research
3. Desire to answer questions and acquire new
knowledge.
4. Desire to get intellectual joy of doing some creative
work;
5. Desire to be of service to society;
6. Desire to get respectability etc.

Even though there desire for research, how we
get research problems?
 When there is perceived difference or discrepancy
between what exists and the ideal or planned situation
 When the reason(s) for this difference is/are unclear
 When the there is a problem raised in the community /public to
be solved.
 There is more than one possible answer to a question or
more than one solution to the problem.

What you do if you have many
problem to be research?
 you have to set criterion to give priority
when you have many research problems. .
 Relevance (How large and how severe is
the problem? Who is affected?) .
 Avoidance of duplication (check if researched
before & reviews to identify if still gap exists).
 Public/community concern:
 Feasibility of the study. (Check resources you will
require?)

Cont…
 Urgency of data needed/ severity (how urgently are results
required?)
 Political acceptability (to what extent government policies
support it?)
 Applicability of results (how likely results can be applied?)
 Ethical acceptability and similar issues should be taken in to
account.

Priority to be given for problems
having highest scores in the criterion.

Research topic
 Once you select research problem, you are expected to
choose research topic/ titles for this problem in clear and
precise way.
 Examples of research topic:
Educational coverage and differential between urban and rural
areas of Oromia Zonal District ,Amhara region Ethiopia

Components of research
 Research has different components.Any research has
table of content,
acronyms (if there is),
introduction,
statement of the
problem,
Objectives,
literature review,
methodology,
results/finding,
Conclusion and recommendation,
appendixes(if exists) and reference
parts.
Let us discus on the some of the
components as follows.

In Research
 There should be good/clear statement of problem/
justification of the burden/gap/need of the research what you
are going to do right now.
 it should clearly and concisely describe the nature of the
problem -what is it, magnitude, distribution (who, where,
when), severity, consequences and possible contributing
factors.
 Objective:- a research will have General and Specific
objectives.
 It should be clearly and precisely stated.
 All objectives of the given research should be answered
after the completion of a research.

LITERATURE REVIEW
 It is a systematic, explicit, and reproducible method of identifying,
evaluating, and synthesizing the existing body of completed and
recorded work produced by researchers, scholars, and
practitioners.
 In a research, we have to search all researches done so far and the to
get gaps.
 critical analysis of the relevant research and non research literature
on the topic being studied should be investigated.

RESEARCH DESIGNS AND RESEARCH
METHODOLOGY
 Depending on the nature and objectives to be achieved in the
research, there are different research/ study designs:
Experimental design
Cross sectional design
Longitudinal designs (cohort , case study etc)

Types of research
 The basic research types are:
Descriptive vs.Analytical
Applied vs. Fundamental
Quantitative vs. Qualitative
Conceptual vs.Empirical

A) Descriptive vs. Analytical
 Descriptive research
 includes surveys and fact-finding enquiries of different kinds.
 It deals with description of the state of affairs as it exist at
now.
 i.e. is describing the existing situation using summery
measures.
 While analytical research, on the other hand, the
researcher has to use facts or information already
available, and analyze these to make a critical evaluation
of the material.

Applied vs. Fundamental
 Applied/action research aims at finding a solution for an
immediate problem facing a society or an industrial/business
organization, whereas fundamental research is mainly
concerned with generalizations and with the formulation
of a theory.
 Fundamental research also called pure/basic
research.

Cont…
 central aim of applied research is to discover a solution for
some pressing practical problem, whereas basic research is
directed towards finding information that has a broad base of
applications and thus, adds to the already existing organized
body of scientific knowledge.

Quantitative vs. Qualitative
 Quantitative research deals with measurements of quantity
or amounts.
 While qualitative research deals with qualitative/categorical
phenomena and hence widely used in behavioral science.

Conceptual vs. Empirical:
 The first related to some abstract idea(s) or theory.
 i.e. developing new ideology/thinking (e.g philosophers ).
 empirical research also called experimental research
relies on experience or observation alone, often without due
regard for system and theory.

RESEARCH METHODOLOGY
 is a way to systematically solve the research problem.
 It may be understood as a science of studying how research
is done scientifically.
 While Research techniques refer to the behavior and
instruments we use in performing research operations such
as making observations, recording data, techniques of
processing data and the like.

Research proposal development
 Research proposal is a draft of your research to
be done in near future.
 Proposal have almost all contents of a research except
the data analysis, discussion , conclusion and
recommendation parts.

Parts of research proposal
 title
 background
 aims and objectives
 literature review
 methodology/methods
 timetable
 budget and resources
 Dissemination
 Reference

WHAT MAKES A GOOD PROPOSAL?
 Relevance, either to the work of the funding body or to the
student‟s course.
 The research is unique, or offers new insight or
development.
 The title, aims and objectives all should be clear and succinct.
 Comprehensive and thorough background research
and literature review has been undertaken.

Cont…
 There should be a good match between the issues going to be
addressed and the approach being adopted.
 The researcher demonstrates relevant background knowledge
and/or experience.
 Timetable, resources and budget have all been worked
out thoroughly, with most eventualities covered.
 Useful policy and practice implications.

Contents of research report
 Title Page
 Contents Page
 List of Illustrations
 Acknowledgements
 Abstract
 Background
 Methodology and Methods
 Findings/Analysis
 Conclusion and recommendation
 References
 Appendices

Introduction to statistical consultancy
 What does statistical consultancy mean?
 Statistical consulting is defined as the collaboration of statisticians with
other professional for the purpose of devising solutions to research
problem.
 it involves two parties: the consultant and the consultee /client.
 It is an interactive creative activity in which a variety of methodological
and statistical problems can come up.
 Statistical consultant provides a range of services to clients including:
Statistical advice, analysis and training.

Cont…
 Clients come from a wide variety of subject areas including Business,
environment, medicine, and governments but they all have one thing in
common ; they wish to collect and analyze data to make evidence- based
decisions.
 Statistical Consultancy services offered internally( as statistical
consultant unit in institution) and externally ( as commercial
employee in international statistical consultancy companies, etc) .
 So there are three option to be employed as statistical consultant;
commercial statistical consult in companies, university statistical
consulting unit for course, PGs or staff son a regular basis and as
freelancer/self employed.

Basic question!
 Who, what, when, where, why, how?
What? The client/
costumer
The
consultant/s
tatistician
The
consultant/
statistician
Discussing
on an issue
•Prior to the start of a
study
• During a study
• After completion of a
study

36
Prior to the start /beginning of a study
 study design
 data collection instruments
 statistical analysis plan
 database support
 randomization schedule
 sample size determination or justification
 writing portions of a grant application or protocol

37
During/the middle of a study
 Randomization issues
 Problems with recruitment, retention, or adherence
 Changes to study design
 Interim analyses

38
After completion/an end of a study
 data analysis
 interpretation of results
 computer outputs
 research findings (can be complicated)
 normality, incorporating covariates, confounders, other statistical
issues
 graphical presentation of findings
 writing statistical analysis/methods section of abstract or manuscript
 assisting in writing results section of abstract or manuscript
 addressing journal reviewer comments

39
Where?
 Statistician’s office?
 Client’s office?
If an office is not available choose a meeting room with
• a positive physical setting, and
• where you will likely not be disturbed
 Make the client feel comfortable before the start of the meeting
• Make eye contact and smile
 Forward your office phone and turn off any Smartphone
 Conducive to taking notes during the consult

40
Why?
 Grant or funding application
 Research project
 Protocol development
 Conference abstract
 Research presentation
 Journal manuscript
 Response to journal or grant reviewer comments

41
How?
That is the subject of the remainder of the talk!
The possible consultation settings are:-
Help desk, peer advice,
by telephone, by email and Skype when clients are far from us.
Through online,
Face to face with data analysis
Group meeting

Thank you!!!
Any ?

Sampling methods and Sample size
Determination
BY:
Tilaye M. (MSc in Biostatistics)
Wollo University, College of Science, Department of Statistics
Training Delivered to High school and PreparatoryTeachers
Kemissie,Ethiopia
Megabit 2009 E.C

Outline
 Definition of terms
 Sampling methods/techniques
 Sample size determination Formulae

Sampling and sampling methods
 Definition of some terms:
 Population:A group of objects under consideration.That‟s
groups to be studied.
 Sampling:The process or method of sample selection from the
population.
 Sampling unit: the ultimate unit to be sampled or elements of
the population to be sampled.

Examples:
 If somebody studies Scio-economic status of the households,
households are the sampling unit.
If one studies performance of freshman students in some
college, the student is the sampling unit.

Cont…
 Sampling frame: is the list of all elements in a population.
 Errors: Sampling and non sampling errors

cont,…
 Sampling error: It is the discrepancy between the
population value and sample value.
 May arise due to in appropriate sampling techniques applied
 Non sampling errors: are errors due to procedural bias
such as:
 Due to incorrect responses
 Measurement/instrumental error
 Errors at different stages in processing the data/ coding and
editing errors.

Why we use sample mostly instead of
census?
 Raise your own evidence for sampling ..

The Need for Sampling instead of
census
 Reduced cost
 Greater speed
 Greater accuracy
 Greater scope
 More detailed information can be obtained.

Types of sampling
 RandomVs Non random
 In random sampling; inclusion or exclusion of
any individual element of the population
depends upon the application of probability
methods and not on a personal judgment.
 Gives non zero chance for each
individuals to be sampled
 Possible to estimate sampling variability
and errors .

While non probability sampling
 Deals with selection of a sample without the use of
probability or randomization.

Probability Sampling Methods
 Simple Random sampling ( using table of random number or
lottery methods)
 Stratified random sampling
 Cluster random sampling
 Systematic random sampling

Simple random sampling is used when:
 The population is convent to get.
 Elements In the population are homogenous.
 List of elements exists.
 The objective is to achieve randomness in drawing the
individual elements of a sample for ensuring that all
possible samples have the same chance of being selected

Stratified random sampling method
 Used when we have different groups in the population
 Classification of population in two different groups called
strata
 The elements across a group are heterogeneous.
 But with in the group there is homogenous elements

In stratified sampling ,
 Samples can be chosen from each strata random fashion
using Simple random sampling!
 Samples should be selected from each strata on proportional
or random ways so that the samples will be representative.

When we use stratified random
sampling?
 If separate estimates of the parameter is needed
 When there is need of comparison b/n separate estimates.
 If the population composed of heterogamous groups but
with in the group there is homogeneity.

Cluster Sampling
 It is particularly useful when the members of the population are
widely scattered geographically.
 So that the population is divided in to different groups called
clusters
 With in the group in clusters there is heterogeneity and across
the group there is homogeneity.

In cluster sampling
 Researchers select all/parts of the cluster based on :
resources availability ( money, human resources ,time and
others)
Accessibility of cluster( should easy to get) and
Scope of the study

Clusters
 Should be selected on randomized way using simple random
sampling
 And then all elements with in the selected cluster may be taken
in to account in the study or you may take parts of elements in
the cluster using simple random sampling
 Remark! It is not a must to take sample from each cluster.
 It can be used when it is costly and difficult to apply simple
random sampling.

Procedures
1. Divide the population into non-overlapping groups (clusters).
2. Obtain a simple random sample of the clusters.
3. Choose /take all the members of the cluster again using SRS.

Systematic sampling
 It needs a complete list of all elements within the population
(sampling frame) is required.
 The procedure starts in determining the first element to be
included in the sample (sample size = n).
 Then the technique is to take the kth item from the sampling
frame. K= N/n
 From the first k elements, selected one randomly let say it is 2nd
and then we chose the (k+n)th value and it continue on such
pattern.

Non-Probability Sampling Methods
 There are various methods of sampling in this category.
 Some of them are explained as follows:
 Convenience sampling : choosing items which easy and
convenient to get.
 Quota sampling: choosing items by giving quota to the
different category.
 Judgmental sampling : ways taking sampling by using
prior or personal judgments that assumed to be
representative.

How sample size determined
 Sample size determination is closely related to statistical
estimation.
 Quite often, you ask, How large a sample is necessary to
make an accurate estimate?
 The answer is not simple,since it depends on three things:
 the maximum error of the estimate,
 the population standard deviation, and
 the degree of confidence.

Cont…
 For example, how close to the true mean do you want to be
(2 units, 5 units, etc.), and how confident do you wish to be
(90, 95, 99%, etc.)?
 For the purpose, it will be assumed that the population
standard deviation of the variable is known or has been
estimated from a previous study.

For continues variable(mean
estimation )
 The smallest sample size, n is given by
𝑛 =
𝑛0
1 +
𝑛0
𝑁
If
𝑛0
𝑁
< 5%, 𝑡ℎ𝑒𝑛 𝑛 = 𝑛0
Where, 𝒏 𝟎=(
𝒁 𝒂/𝟐∗𝝈
𝑬
) 𝟐

Sample size for categorical variable (
estimation of proportion)
For Proportion P, the sample size n, is given by
𝑛 =
𝑛0
1+
𝑛0
𝑁
Where, 𝑛0 = 𝑝(1 − 𝑝)(
𝑍 𝑎/2
𝐸
)2
Condition to use 𝑛0 𝑎𝑠 𝑛 𝑖𝑠 𝑎𝑠 𝑠𝑒𝑒𝑛 𝑏𝑒𝑓𝑜𝑟𝑒.
Where
- 𝑍 𝛼
2
is the critical value obtained from the table/ Statistical
package
- 𝑝 is the estimated sample proportion
- 𝐸 the marginal error that can be tolerate

Thank you!!!
Any ?
Contact address: gc2003@ymail.com

Ppt research Methods and statistical consultancy

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