R allows users to perform calculations, analyze data, and create visualizations through commands and functions. This document discusses R basics including commands, functions, arguments, reading in data from files, and performing descriptive statistics. Key points covered include using the pipe operator (%)>% to chain multiple functions together, loading and summarizing data, and obtaining descriptive statistics for single and multiple variables as well as grouped variables.
This document provides information about a business course, including that there will be class on Labor Day and lab materials are available on Canvas. It discusses fixed effects in models and how to include them in R scripts. Predicted values from models are covered, along with using residuals to detect outliers and interpreting interactions between variables in models. The document provides examples of adding interaction terms to model formulas and interpreting the results.
This document provides an overview of data processing techniques in R, including filtering, mutating, and working with different variable types. It discusses using filter() to subset data frames based on logical criteria, saving filtered data to new data frames. It also covers using mutate() to create new variables and recode existing ones. The if_else() function and applying conditional logic when assigning values is explained. The document concludes with a brief overview of variable types in R like numeric, character, and factor, as well as functions for converting between types and examples of built-in and package functions for analysis.
Mixed Effects Models - Centering and TransformationsScott Fraundorf
This document provides information about analyzing a dataset called numerosity that contains reaction time (RT) data from a dot counting task and self-reported math anxiety ratings. It discusses centering the numerosity (number of dots) and anxiety variables, including mean centering, centering around other values, and the difference between grand-mean and cluster-mean centering. It also covers transforming the numerosity variable using logarithms due to the non-linear relationship with RT. The goal is to build mixed effects models to examine the effects of numerosity and anxiety on RT.
There are a few potential issues with modeling the data this way:
1. Students are nested within classrooms. A student's outcomes may be more similar to others in their classroom compared to students in other classrooms, due to shared classroom factors. This violates the independence assumption of ordinary least squares regression.
2. Classroom-level factors like teacher quality are not included in the model but likely influence student outcomes. Failing to account for these could lead to omitted variable bias.
3. The error terms for students within the same classroom may not be independent as assumed, since classroom factors induce correlation.
To properly account for the nested data structure, we need to model the classroom as a second level in a multilevel
The document discusses introducing mixed effects models. It focuses on fixed effects, which are the effects of interest. This week covers sample datasets, theoretical models, fitting models in R, and interpreting parameters like slopes and intercepts. The sample dataset examines factors like newcomers and experience that influence how long teams take to assemble phones. The document uses this example to demonstrate key steps in modeling fixed effects, such as estimating slopes, intercepts, and conducting hypothesis tests on parameters.
This document provides information and examples related to interpreting interaction effects in statistical models. It begins with an overview of how to interpret numerical interaction terms and then provides several examples of interactions between variables and their interpretation. These include examples involving intrinsic motivation and autonomy on learning, number of choices and maximizing strategy on satisfaction, language proficiency and word frequency on translation accuracy, and more. It then shifts to discussing model comparison, including nested models, hypothesis testing using likelihood ratio tests, and comparing models.
The document discusses introducing random slopes to multilevel models. Random slopes allow the relationship between a predictor variable (like tutor hours) to vary across levels (like schools). This accounts for differences in how effective an intervention may be depending on context. The notation for random slopes models is presented, with classroom and student models nested within school-level models. Implementing random slopes helps address non-independence of observations and better estimate variability.
This document provides information about a business course, including that there will be class on Labor Day and lab materials are available on Canvas. It discusses fixed effects in models and how to include them in R scripts. Predicted values from models are covered, along with using residuals to detect outliers and interpreting interactions between variables in models. The document provides examples of adding interaction terms to model formulas and interpreting the results.
This document provides an overview of data processing techniques in R, including filtering, mutating, and working with different variable types. It discusses using filter() to subset data frames based on logical criteria, saving filtered data to new data frames. It also covers using mutate() to create new variables and recode existing ones. The if_else() function and applying conditional logic when assigning values is explained. The document concludes with a brief overview of variable types in R like numeric, character, and factor, as well as functions for converting between types and examples of built-in and package functions for analysis.
Mixed Effects Models - Centering and TransformationsScott Fraundorf
This document provides information about analyzing a dataset called numerosity that contains reaction time (RT) data from a dot counting task and self-reported math anxiety ratings. It discusses centering the numerosity (number of dots) and anxiety variables, including mean centering, centering around other values, and the difference between grand-mean and cluster-mean centering. It also covers transforming the numerosity variable using logarithms due to the non-linear relationship with RT. The goal is to build mixed effects models to examine the effects of numerosity and anxiety on RT.
There are a few potential issues with modeling the data this way:
1. Students are nested within classrooms. A student's outcomes may be more similar to others in their classroom compared to students in other classrooms, due to shared classroom factors. This violates the independence assumption of ordinary least squares regression.
2. Classroom-level factors like teacher quality are not included in the model but likely influence student outcomes. Failing to account for these could lead to omitted variable bias.
3. The error terms for students within the same classroom may not be independent as assumed, since classroom factors induce correlation.
To properly account for the nested data structure, we need to model the classroom as a second level in a multilevel
The document discusses introducing mixed effects models. It focuses on fixed effects, which are the effects of interest. This week covers sample datasets, theoretical models, fitting models in R, and interpreting parameters like slopes and intercepts. The sample dataset examines factors like newcomers and experience that influence how long teams take to assemble phones. The document uses this example to demonstrate key steps in modeling fixed effects, such as estimating slopes, intercepts, and conducting hypothesis tests on parameters.
This document provides information and examples related to interpreting interaction effects in statistical models. It begins with an overview of how to interpret numerical interaction terms and then provides several examples of interactions between variables and their interpretation. These include examples involving intrinsic motivation and autonomy on learning, number of choices and maximizing strategy on satisfaction, language proficiency and word frequency on translation accuracy, and more. It then shifts to discussing model comparison, including nested models, hypothesis testing using likelihood ratio tests, and comparing models.
The document discusses introducing random slopes to multilevel models. Random slopes allow the relationship between a predictor variable (like tutor hours) to vary across levels (like schools). This accounts for differences in how effective an intervention may be depending on context. The notation for random slopes models is presented, with classroom and student models nested within school-level models. Implementing random slopes helps address non-independence of observations and better estimate variability.
This document discusses empirical logit models. It begins by clarifying logit models, which use a logit link function to model binary dependent variables. It then discusses Poisson regression models. The document notes that empirical logit can be used to model low-frequency events like errors or rare outcomes that may have probabilities close to 0. Empirical logit makes extreme probabilities less extreme by adding 0.5 to the numerator and denominator when calculating the logit. It concludes by discussing how to implement empirical logit models using the psycholing package in R.
Statistics is the study of collecting, organizing, analyzing, and interpreting data. It deals with all aspects of data collection and analysis. Some common applications of statistics include agriculture, business/economics, marketing research, education, and medicine. There are different types of variables that can be measured, including qualitative vs. quantitative variables and discrete vs. continuous variables. Common graphical representations of data include bar graphs, pie charts, histograms, and scatter plots. Measures of central tendency summarize data by identifying a central value, such as the mean, median, and mode.
Flow Metrics: What They Are & Why You Need ThemTasktop
When it comes to assessing an IT transformation (such as Agile and DevOps), performance metrics have come under intense scrutiny. Traditional performance metrics, such as counting the number of lines of code and the number of software bugs should be used with caution, because there are bugs that are not worth fixing and code that is not worth maintaining. These old-school performance metrics represent activities, not outcomes. To visualize and optimize the business value of your software delivery, you need to find a way to measure business outcomes. To do that, we need flow metrics.
During this on-demand webinar, Dominica DeGrandis presents five key flow metrics that reveal trends on desirable business outcomes – such as faster time-to-market, responsiveness to customers, and predictable release timeframes – and explains how to implement them at your organization to measure and improve the impact and value of software products on your business.
Using Large Language Models in 10 Lines of CodeGautier Marti
Modern NLP models can be daunting: No more bag-of-words but complex neural network architectures, with billions of parameters. Engineers, financial analysts, entrepreneurs, and mere tinkerers, fear not! You can get started with as little as 10 lines of code.
Presentation prepared for the Abu Dhabi Machine Learning Meetup Season 3 Episode 3 hosted at ADGM in Abu Dhabi.
Forecasting warranty returns with Wiebull FitTonda MacLeod
Analyze Wise provides a statistical analysis of warranty return data to forecast future returns using a Weibull distribution model. The analysis involves obtaining time-to-failure data from historical warranty returns, performing a regression to identify the best fitting distribution model and associated parameters, and using the model to predict return counts by time period. The forecasts can help companies plan repair resources, manage customer relationships, and evaluate warranty expenses and product performance.
The document discusses multiple linear regression and partial correlation. It explains that multiple regression allows one to analyze the unique contribution of predictor variables to an outcome variable after accounting for the effects of other predictor variables. Partial correlation similarly examines the relationship between two variables while controlling for a third, but only considers two variables, whereas multiple regression examines the effects of multiple predictor variables simultaneously. Examples are given comparing the correlation between height and weight with and without controlling for other relevant variables like gender, age, exercise habits, etc.
This document provides an introduction to R programming. It discusses that R is an open source programming language for statistical analysis and graphics. It is used widely in data science due to being free, having a strong user community, and having the ability to implement advanced statistical methods. The document then covers downloading and installing R, the basic R environment including the command window and scripts, basic programming objects like vectors and data frames, and how to import and work with datasets in R. It emphasizes that R has powerful but can be difficult to learn due to being command-driven without commercial support.
Language-agnostic data analysis workflows and reproducible researchAndrew Lowe
This was a talk that I gave at CERN at the Inter-experimental Machine Learning (IML) Working Group Meeting in April 2017 about language-agnostic (or polyglot) analysis workflows. I show how it is possible to work in multiple languages and switch between them without leaving the workflow you started. Additionally, I demonstrate how an entire workflow can be encapsulated in a markdown file that is rendered to a publishable paper with cross-references and a bibliography (and with raw LaTeX file produced as a by-product) in a simple process, making the whole analysis workflow reproducible. For experimental particle physics, ROOT is the ubiquitous data analysis tool, and has been for the last 20 years old, so I also talk about how to exchange data to and from ROOT.
R is an open source statistical programming language and software environment used widely for statistical analysis and graphics. This document provided an introduction to using R, including downloading and installing R, the basic R environment and interface, help resources, loading and using packages, reading data into R from files, and performing common descriptive statistics and linear regression modeling. Examples were provided using built-in and example datasets to demonstrate summarizing data, exploring variables, and fitting simple statistical models in R.
This document discusses using R for initial data analysis. It covers loading data into R from files or by typing it in, exploring and visualizing the data using basic statistics and graphs, and saving outputs. R allows importing data from various sources, creating and editing data structures, and exporting objects and plots for sharing results. The key is becoming familiar with R's programming environment and functions for summarizing, transforming, and visualizing data.
R is a free implementation of the S programming language for statistical analysis and graphics. It allows for both interactive analysis and programming. The document discusses reading data into R from various sources, performing operations and computations on data frames, creating subsets of data, and producing graphics. Key points covered include using formulas for modeling, designing legible graphs, and exporting graphs to other formats like PDF.
Introduction to R Short course Fall 2016Spencer Fox
The document provides instructions for an introductory R session, including downloading materials from a GitHub repository and opening an R project file. It outlines logging in, downloading an R project folder containing intro materials, and opening the project file in RStudio.
The document discusses creating an optimized algorithm in R. It covers writing functions and algorithms in R, creating R packages, and optimizing code performance using parallel computing and high performance computing. Key steps include reviewing existing algorithms, identifying gaps, testing and iterating a new algorithm, publishing the work, and making the algorithm available to others through an R package.
The document describes Hadoop MapReduce and its key concepts. It discusses how MapReduce allows for parallel processing of large datasets across clusters of computers using a simple programming model. It provides details on the MapReduce architecture, including the JobTracker master and TaskTracker slaves. It also gives examples of common MapReduce algorithms and patterns like counting, sorting, joins and iterative processing.
This document provides an overview of the basics of R. It discusses why R is useful, outlines its interface and workspace, describes how to get help and install packages, and explains some key concepts like objects, functions, and the search path. The document is intended to introduce new users to commonly used R functions and features to get started with the programming language.
This document provides an overview of the basics of R. It discusses why R is useful, outlines its interface and workspace, describes how to get help and install packages, and explains some key concepts like objects, functions, and the search path. The document is intended to introduce new users to commonly used R functions and features to get started with the programming language.
This document provides an overview of the basics of R including why R is used, tutorials and links for learning R, an overview of the R interface and workspace, and how to get help in R. It discusses that R is a free and open-source statistical programming language used for statistical analysis and graphics. It has a steep learning curve due to the interactive nature of analyzing data through chained commands rather than single procedures. Help is provided through a built-in system and various online tutorials.
Modeling in R Programming Language for Beginers.pptanshikagoel52
This document provides an overview of the basics of R. It discusses why R is useful, outlines its interface and workspace, describes how to get help and install packages, and explains some key concepts like objects, functions, and the search path. The document is intended to introduce new users to commonly used R functions and features to get started with the programming language.
A program is a sequence of instructions that are run by the processor. To run a program, it must be compiled into binary code and given to the operating system. The OS then gives the code to the processor to execute. Functions allow code to be reused by defining operations and optionally returning values. Strings are sequences of characters that can be manipulated using indexes and methods. Common string methods include upper() and concatenation using +.
A program is a sequence of instructions that are run by the processor. To run a program, it must be compiled into binary code and given to the operating system. The OS then gives the code to the processor to execute. Functions allow code to be reused by defining operations and returning values. Strings are sequences of characters that can be manipulated using indexes and methods. Common string methods include upper() and concatenation using +.
This document discusses empirical logit models. It begins by clarifying logit models, which use a logit link function to model binary dependent variables. It then discusses Poisson regression models. The document notes that empirical logit can be used to model low-frequency events like errors or rare outcomes that may have probabilities close to 0. Empirical logit makes extreme probabilities less extreme by adding 0.5 to the numerator and denominator when calculating the logit. It concludes by discussing how to implement empirical logit models using the psycholing package in R.
Statistics is the study of collecting, organizing, analyzing, and interpreting data. It deals with all aspects of data collection and analysis. Some common applications of statistics include agriculture, business/economics, marketing research, education, and medicine. There are different types of variables that can be measured, including qualitative vs. quantitative variables and discrete vs. continuous variables. Common graphical representations of data include bar graphs, pie charts, histograms, and scatter plots. Measures of central tendency summarize data by identifying a central value, such as the mean, median, and mode.
Flow Metrics: What They Are & Why You Need ThemTasktop
When it comes to assessing an IT transformation (such as Agile and DevOps), performance metrics have come under intense scrutiny. Traditional performance metrics, such as counting the number of lines of code and the number of software bugs should be used with caution, because there are bugs that are not worth fixing and code that is not worth maintaining. These old-school performance metrics represent activities, not outcomes. To visualize and optimize the business value of your software delivery, you need to find a way to measure business outcomes. To do that, we need flow metrics.
During this on-demand webinar, Dominica DeGrandis presents five key flow metrics that reveal trends on desirable business outcomes – such as faster time-to-market, responsiveness to customers, and predictable release timeframes – and explains how to implement them at your organization to measure and improve the impact and value of software products on your business.
Using Large Language Models in 10 Lines of CodeGautier Marti
Modern NLP models can be daunting: No more bag-of-words but complex neural network architectures, with billions of parameters. Engineers, financial analysts, entrepreneurs, and mere tinkerers, fear not! You can get started with as little as 10 lines of code.
Presentation prepared for the Abu Dhabi Machine Learning Meetup Season 3 Episode 3 hosted at ADGM in Abu Dhabi.
Forecasting warranty returns with Wiebull FitTonda MacLeod
Analyze Wise provides a statistical analysis of warranty return data to forecast future returns using a Weibull distribution model. The analysis involves obtaining time-to-failure data from historical warranty returns, performing a regression to identify the best fitting distribution model and associated parameters, and using the model to predict return counts by time period. The forecasts can help companies plan repair resources, manage customer relationships, and evaluate warranty expenses and product performance.
The document discusses multiple linear regression and partial correlation. It explains that multiple regression allows one to analyze the unique contribution of predictor variables to an outcome variable after accounting for the effects of other predictor variables. Partial correlation similarly examines the relationship between two variables while controlling for a third, but only considers two variables, whereas multiple regression examines the effects of multiple predictor variables simultaneously. Examples are given comparing the correlation between height and weight with and without controlling for other relevant variables like gender, age, exercise habits, etc.
This document provides an introduction to R programming. It discusses that R is an open source programming language for statistical analysis and graphics. It is used widely in data science due to being free, having a strong user community, and having the ability to implement advanced statistical methods. The document then covers downloading and installing R, the basic R environment including the command window and scripts, basic programming objects like vectors and data frames, and how to import and work with datasets in R. It emphasizes that R has powerful but can be difficult to learn due to being command-driven without commercial support.
Language-agnostic data analysis workflows and reproducible researchAndrew Lowe
This was a talk that I gave at CERN at the Inter-experimental Machine Learning (IML) Working Group Meeting in April 2017 about language-agnostic (or polyglot) analysis workflows. I show how it is possible to work in multiple languages and switch between them without leaving the workflow you started. Additionally, I demonstrate how an entire workflow can be encapsulated in a markdown file that is rendered to a publishable paper with cross-references and a bibliography (and with raw LaTeX file produced as a by-product) in a simple process, making the whole analysis workflow reproducible. For experimental particle physics, ROOT is the ubiquitous data analysis tool, and has been for the last 20 years old, so I also talk about how to exchange data to and from ROOT.
R is an open source statistical programming language and software environment used widely for statistical analysis and graphics. This document provided an introduction to using R, including downloading and installing R, the basic R environment and interface, help resources, loading and using packages, reading data into R from files, and performing common descriptive statistics and linear regression modeling. Examples were provided using built-in and example datasets to demonstrate summarizing data, exploring variables, and fitting simple statistical models in R.
This document discusses using R for initial data analysis. It covers loading data into R from files or by typing it in, exploring and visualizing the data using basic statistics and graphs, and saving outputs. R allows importing data from various sources, creating and editing data structures, and exporting objects and plots for sharing results. The key is becoming familiar with R's programming environment and functions for summarizing, transforming, and visualizing data.
R is a free implementation of the S programming language for statistical analysis and graphics. It allows for both interactive analysis and programming. The document discusses reading data into R from various sources, performing operations and computations on data frames, creating subsets of data, and producing graphics. Key points covered include using formulas for modeling, designing legible graphs, and exporting graphs to other formats like PDF.
Introduction to R Short course Fall 2016Spencer Fox
The document provides instructions for an introductory R session, including downloading materials from a GitHub repository and opening an R project file. It outlines logging in, downloading an R project folder containing intro materials, and opening the project file in RStudio.
The document discusses creating an optimized algorithm in R. It covers writing functions and algorithms in R, creating R packages, and optimizing code performance using parallel computing and high performance computing. Key steps include reviewing existing algorithms, identifying gaps, testing and iterating a new algorithm, publishing the work, and making the algorithm available to others through an R package.
The document describes Hadoop MapReduce and its key concepts. It discusses how MapReduce allows for parallel processing of large datasets across clusters of computers using a simple programming model. It provides details on the MapReduce architecture, including the JobTracker master and TaskTracker slaves. It also gives examples of common MapReduce algorithms and patterns like counting, sorting, joins and iterative processing.
This document provides an overview of the basics of R. It discusses why R is useful, outlines its interface and workspace, describes how to get help and install packages, and explains some key concepts like objects, functions, and the search path. The document is intended to introduce new users to commonly used R functions and features to get started with the programming language.
This document provides an overview of the basics of R. It discusses why R is useful, outlines its interface and workspace, describes how to get help and install packages, and explains some key concepts like objects, functions, and the search path. The document is intended to introduce new users to commonly used R functions and features to get started with the programming language.
This document provides an overview of the basics of R including why R is used, tutorials and links for learning R, an overview of the R interface and workspace, and how to get help in R. It discusses that R is a free and open-source statistical programming language used for statistical analysis and graphics. It has a steep learning curve due to the interactive nature of analyzing data through chained commands rather than single procedures. Help is provided through a built-in system and various online tutorials.
Modeling in R Programming Language for Beginers.pptanshikagoel52
This document provides an overview of the basics of R. It discusses why R is useful, outlines its interface and workspace, describes how to get help and install packages, and explains some key concepts like objects, functions, and the search path. The document is intended to introduce new users to commonly used R functions and features to get started with the programming language.
A program is a sequence of instructions that are run by the processor. To run a program, it must be compiled into binary code and given to the operating system. The OS then gives the code to the processor to execute. Functions allow code to be reused by defining operations and optionally returning values. Strings are sequences of characters that can be manipulated using indexes and methods. Common string methods include upper() and concatenation using +.
A program is a sequence of instructions that are run by the processor. To run a program, it must be compiled into binary code and given to the operating system. The OS then gives the code to the processor to execute. Functions allow code to be reused by defining operations and returning values. Strings are sequences of characters that can be manipulated using indexes and methods. Common string methods include upper() and concatenation using +.
A program is a sequence of instructions that are run by the processor. To run a program, it must be compiled into binary code and given to the operating system. The OS then tells the processor to execute the program. Functions allow code to be reused by defining operations that take in arguments and return values. Strings are sequences of characters that can be accessed by index and manipulated with methods like upper() that return new strings.
A program is a sequence of instructions that are run by the processor. To run a program, it must be compiled into binary code and given to the operating system. The OS then gives the code to the processor to execute. Functions allow code to be reused by defining operations and returning values. Strings are sequences of characters that can be manipulated using indexes and methods. Common string methods include upper() and concatenation using +.
A program is a sequence of instructions that are run by the processor. To run a program, it must be compiled into binary code and given to the operating system. The OS then gives the code to the processor to execute. Functions allow code to be reused by defining operations and returning values. Strings are sequences of characters that can be manipulated using indexes and methods. Common string methods include upper() and concatenation using +.
A program is a sequence of instructions that are run by the processor. To run a program, it must be compiled into binary code and given to the operating system. The OS then gives the code to the processor to execute. Functions allow code to be reused by defining operations and returning values. Strings are sequences of characters that can be accessed by index and manipulated with methods like upper() that return new strings.
A program is a sequence of instructions that are run by the processor. To run a program, it must be compiled into binary code and given to the operating system. The OS then gives the code to the processor to execute. Functions allow code to be reused by defining operations and returning values. Strings are sequences of characters that can be accessed by index and manipulated with methods like upper() that return new strings.
Similar to Mixed Effects Models - Descriptive Statistics (20)
Mixed Effects Models - Signal Detection TheoryScott Fraundorf
Signal detection theory provides a framework for analyzing categorical judgments by distinguishing between sensitivity and response bias. Sensitivity refers to the ability to discriminate between signal and noise, such as detecting whether sentence pairs are the same color. Response bias reflects the overall tendency to respond in a certain category, such as a propensity to judge sentences as grammatical. Signal detection theory models allow researchers to separately measure how experimental manipulations influence these components of performance.
The document discusses power analysis and statistical power. It notes that power analysis allows researchers to determine if their planned sample size is large enough to detect effects of interest and not too large. Conducting power analyses can help ensure efficient use of resources and avoid issues like p-hacking. Understanding power is also important for interpreting null results and replication failures, as low-powered studies are unlikely to find small effects.
This document discusses effect size and how to establish causality in longitudinal data analysis. It begins by reviewing autocorrelation and how to account for it in mixed effects models. It then discusses cross-lagged models, where including lags of variables can help determine whether A causes B or B causes A. Establishing causality further requires showing the relationship is directional by testing models in both directions. The document provides an example using a diary study to show that emotional support attempts cause increased warmth, not vice versa. It also discusses how effect size compares to statistical significance and how to interpret the size of different effects.
This document discusses issues that can arise with missing or incomplete data in statistical models. It covers several types of problems, including rank deficiency caused by linear dependencies between predictors, and incomplete designs where certain combinations of factor levels are not represented in the data. It also discusses different patterns of missing data and how the mechanism that led to certain data points being missing (missing completely at random, missing at random, or missing not at random) impacts which techniques are appropriate for handling the missing values, such as casewise deletion, listwise deletion, or imputation methods. Examples using the lmer function in R and a dataset on cortisol levels are provided to illustrate these concepts.
This document provides an introduction to logit models for categorical outcomes. It discusses how logit models use a logistic link function to model the log odds of categorical outcomes as a linear combination of predictors while accounting for random effects. Key points covered include probabilities, odds, the logit transformation, interpreting model parameters, and implementing logit models in R using the glmer() function from the lme4 package.
1. Post-hoc comparisons allow testing differences between individual levels or cells in an experiment after fitting a linear mixed effects model. The Tukey test, available via the emmeans package, corrects for multiple comparisons.
2. Estimated marginal means (EMMs) report what cell means would be if covariates were equal across conditions, providing a hypothetical adjustment. EMMs can be compared to test effects averaging over other variables.
3. Both post-hoc comparisons and EMMs require fitting an appropriate linear mixed effects model first before making inferences about condition differences.
Mixed Effects Models - Crossed Random EffectsScott Fraundorf
This document discusses crossed random effects analysis using an experimental dataset measuring response times for students learning English naming words. The dataset includes 60 subjects presented with 49 words each, with measurements of years of study and word frequency as variables of interest. It describes fitting a linear mixed effects model with random intercepts for subject and word to account for non-independence of observations. It also discusses joining additional word frequency data from another file and adding word frequency as a fixed effect. Finally, it introduces the concepts of between-subjects and within-subjects variables to determine what random slopes may be relevant.
This document discusses including level-2 variables in multilevel models. It explains that level-2 variables characterize groups (like classrooms) and are invariant within groups. An example adds the variable "TeacherTheory" to characterize teachers' mindset and explain differences between classrooms. This reduces unexplained classroom variance but does not change the level-1 model or residuals. Cross-level interactions like the effect of a student's mindset depending on their teacher's mindset can also be added. Including level-2 variables provides more information about group differences but does not alter the basic multilevel structure.
This document discusses an upcoming course on using mixed effects models in psychology. The course will cover applying mixed effects models to common research designs, fitting models in R, and addressing issues that arise. Mixed effects models are motivated by research designs involving multiple random effects, nested random effects, crossed random effects, categorical dependent variables, and continuous predictors. Accounting for these complex sampling procedures and non-independent observations is important for making valid statistical inferences.
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إضغ بين إيديكم من أقوى الملازم التي صممتها
ملزمة تشريح الجهاز الهيكلي (نظري 3)
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تتميز هذهِ الملزمة بعِدة مُميزات :
1- مُترجمة ترجمة تُناسب جميع المستويات
2- تحتوي على 78 رسم توضيحي لكل كلمة موجودة بالملزمة (لكل كلمة !!!!)
#فهم_ماكو_درخ
3- دقة الكتابة والصور عالية جداً جداً جداً
4- هُنالك بعض المعلومات تم توضيحها بشكل تفصيلي جداً (تُعتبر لدى الطالب أو الطالبة بإنها معلومات مُبهمة ومع ذلك تم توضيح هذهِ المعلومات المُبهمة بشكل تفصيلي جداً
5- الملزمة تشرح نفسها ب نفسها بس تكلك تعال اقراني
6- تحتوي الملزمة في اول سلايد على خارطة تتضمن جميع تفرُعات معلومات الجهاز الهيكلي المذكورة في هذهِ الملزمة
واخيراً هذهِ الملزمة حلالٌ عليكم وإتمنى منكم إن تدعولي بالخير والصحة والعافية فقط
كل التوفيق زملائي وزميلاتي ، زميلكم محمد الذهبي 💊💊
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A proprietary approach developed by bringing together the best of learning theories from Psychology, design principles from the world of visualization, and pedagogical methods from over a decade of training experience, that enables you to: Learn better, faster!
A Visual Guide to 1 Samuel | A Tale of Two HeartsSteve Thomason
These slides walk through the story of 1 Samuel. Samuel is the last judge of Israel. The people reject God and want a king. Saul is anointed as the first king, but he is not a good king. David, the shepherd boy is anointed and Saul is envious of him. David shows honor while Saul continues to self destruct.
Temple of Asclepius in Thrace. Excavation resultsKrassimira Luka
The temple and the sanctuary around were dedicated to Asklepios Zmidrenus. This name has been known since 1875 when an inscription dedicated to him was discovered in Rome. The inscription is dated in 227 AD and was left by soldiers originating from the city of Philippopolis (modern Plovdiv).
3. Week 2.1: Descriptive Statistics in R
! R commands & functions
! Tidyverse & the Pipe Operator
! Multiple Functions
! Reading in data
! Saving R scripts
! Descriptive statistics
! 1 variable
! 2 variable
! Grouping
! Plotting
! Scatterplot
! Bar graph
4. R Commands
! Simplest way to interact with R is by
typing in commands at the > prompt:
R STUDIO R
5. R as a Calculator
! Typing in a simple calculation shows us
the result:
! 608 + 28
! What’s 11527 minus 283?
! Some more examples:
! 400 / 65 (division)
! 2 * 4 (multiplication)
! 5 ^ 2 (exponentiation)
6. Functions
! More complex calculations can be done
with functions:
! sqrt(64)
! Can often read these
left to right (“square root of 64”)
! What do you think
this means?
! abs(-7)
What the function
is (square root)
In parenthesis: What
we want to perform the
function on
7. Arguments
! Some functions have settings
(“arguments”) that we can adjust:
! round(3.14)
- Rounds off to the nearest integer (zero
decimal places)
! round(3.14, digits=1)
- One decimal place
8. Week 2.1: Descriptive Statistics in R
! R commands & functions
! Tidyverse & the Pipe Operator
! Multiple Functions
! Reading in data
! Saving R scripts
! Descriptive statistics
! 1 variable
! 2 variable
! Grouping
! Plotting
! Scatterplot
! Bar graph
9. Tidyverse & the Pipe Operator
! tidyverse is a very popular add-on
package for many basic data-processing
tasks in R
! 2 steps to using:
! Install Tidyverse—only needs to be done
once per computer
10. Installing Tidyverse: RStudio
• Tools menu -> Install
Packages…
• Type in tidyverse
• Leave Install
Dependencies
checked
• Grabs the other packages
that tidyverse uses
• Only need to do this once
per computer!
11. Installing Tidyverse : R
• Packages & Data
menu -> Package
Installer -> Get List
• Find tidyverse
• Make sure to check
Install Dependencies
• Grabs the other packages
that tidyverse uses
• Only need to do this once
per computer!
12. Tidyverse & the Pipe Operator
! tidyverse is a very popular add-on
package for many basic data-processing
tasks in R
! 2 steps to using:
! Install Tidyverse—only needs to be done
once per computer
! Load Tidyverse—once per R session
! library(tidyverse)
13. Tidyverse & the Pipe Operator
! tidyverse provides another interface to
functions—the pipe operator
! a %>% b()
! Start with a and
apply function b()to it
! 3.14 %>% round()
! Helpful when we
have multiple
functions (as we’ll
see in a moment)
14. Week 2.1: Descriptive Statistics in R
! R commands & functions
! Tidyverse & the Pipe Operator
! Multiple Functions
! Reading in data
! Saving R scripts
! Descriptive statistics
! 1 variable
! 2 variable
! Grouping
! Plotting
! Scatterplot
! Bar graph
16. Multiple Functions
! The pipe operator makes it easy to do
multiple functions in a row
! -16 %>% sqrt() %>% abs()
• Start with -16
• Then take the square root
• Then take the absolute value
! Don't get scared when you see multiple
pipes!
- Just read left to right
17. Using Multiple Numbers at Once
! When we want to use multiple
numbers, we concatenate them
! c(2,6,16)
- A list of the numbers 2, 6, and 16
! Sometimes a computation requires multiple
numbers
- c(2,6,16) %>% mean()
! Also a quick way to do the same thing to
multiple different numbers:
- c(16,100,144) %>% sqrt()
CONCATENATE
18. Week 2.1: Descriptive Statistics in R
! R commands & functions
! Tidyverse & the Pipe Operator
! Multiple Functions
! Reading in data
! Saving R scripts
! Descriptive statistics
! 1 variable
! 2 variable
! Grouping
! Plotting
! Scatterplot
! Bar graph
19. Modules: Week 2.1: experiment.csv
! Reading plausible versus implausible
sentences
! “Scott chopped the carrots with a knife.”
“Scott chopped the carrots with a spoon.”
Measure
reading time
on final
word
Note: Simulated data; not a real experiment.
20. Modules: Week 2.1: experiment.csv
! Reading plausible versus implausible
sentences
! Reading time on critical word
! 36 subjects
! Each subject sees 30 items (sentences):
half plausible, half implausible
! Interested in changes over time, so we’ll
track number of trials remaining (29 vs
28 vs 27 vs 26…)
21. Reading in Data
! Make sure you have the dataset at this
point if you want to follow along:
Canvas "
Modules "
Week 2.1 "
experiment.csv
22. Reading in Data – RStudio
! Navigate to the
folder in lower-right
! More ->
Set as Working Directory
! Open a “comma-separated value” file:
- experiment <-read.csv('experiment.csv')
Name of the “dataframe”
we’re creating (whatever
we want to call this dataset) read.csv is the
function name
File name
23. Reading in Data – RStudio
! Navigate to the
folder in lower-right
! More ->
Set as Working Directory
! Open a “comma-separated value” file:
- experiment <-read.csv('experiment.csv’)
• General form of this:
dataframe.name <-read.csv('filename')
24. Reading in Data – Regular R
! Read in a “comma-separated value” file:
- experiment <- read.csv
('/Users/scottfraundorf/Desktop/experiment.csv')
Name of the “dataframe”
we’re creating (whatever
we want to call this dataset)
read.csv is the function
name
Folder & file name
• Drag & drop the file into R to get the
full folder & filename
25. Looking at the Data: Summary
! A “big picture” of the dataset:
! experiment %>% summary()
! summary() is a very important function!
! Basic info & descriptive statistics
! Check to make sure the data are correct
26. Looking at the Data: Summary
! A “big picture” of the dataset:
! experiment %>% summary()
! We can use $ to refer to a specific
column/variable in our dataset:
! experiment$RT %>% summary()
27. Looking at the Data: Raw Data
! Let’s look at the data!
! experiment
28. Looking at the Data: Raw Data
! Ack! That’s too much!
How about just a few rows?
! experiment %>% head()
! experiment %>% head(n=10)
29. Reading in Data: Other Formats
! Excel:
! Install the readxl package (only
needs to be done once)
- install.packages('readxl')
- Then, to read in Excel data:
- library(readxl)
- experiment <-
read_excel('/Users/scottfraundorf/Des
ktop/experiment.xlsx', sheet=2)
Excel files can have multiple sheets/tabs. In this
case, we are saying to use sheet 2.
30. Reading in Data: Other Formats
! SPSS:
! Uses the haven package—already
installed as part of tidyverse
! Then, to read in SPSS data:
- library(haven)
- experiment <-
read_spss('/Users/scottfraundorf/Desk
top/experiment.spss')
- This package also includes read_sas and
read_stata
31. Week 2.1: Descriptive Statistics in R
! R commands & functions
! Tidyverse & the Pipe Operator
! Multiple Functions
! Reading in data
! Saving R scripts
! Descriptive statistics
! 1 variable
! 2 variable
! Grouping
! Plotting
! Scatterplot
! Bar graph
32. R Scripts
! Save & reuse commands with a script
R STUDIO
R
File -> New Document
33. R Scripts
! Run commands without typing them all
again
! R Studio:
! Code -> Run Region -> Run All: Run entire script
! Code -> Run Line(s): Run just what you’ve
highlighted/selected
! R:
- Highlight the section of script you want to run
- Edit -> Execute
! Keyboard shortcut for this:
- Ctrl+Enter (PC), ⌘+Enter (Mac)
34. R Scripts
! Saves times when re-running analyses
! Other advantages?
! Some:
- Documentation for yourself
- Documentation for others
- Reuse with new analyses/experiments
- Quicker to run—can automatically
perform one analysis after another
35. R Scripts—Comments
! Add # before a line to make it a
comment
- Not commands to R, just notes to self
(or other readers)
• Can also add a # to make the rest of a
line a comment
• experiment$RT %>% summary() #awesome
36. Week 2.1: Descriptive Statistics in R
! R commands & functions
! Tidyverse & the Pipe Operator
! Multiple Functions
! Reading in data
! Saving R scripts
! Descriptive statistics
! 1 variable
! 2 variable
! Grouping
! Plotting
! Scatterplot
! Bar graph
37. Descriptive Statistics
! So far, we’ve used summary() to get a
high-level overview of our data
! Now, let’s use tidyverse to start testing
specific descriptive statistics
38. Descriptive Statistics
! Let’s try getting the mean of the RT column
! We start with our experiment dataframe…
experiment %>%
Dataframe name
39. Descriptive Statistics
! Let’s try getting the mean of the RT column
! We start with our experiment dataframe…
! …then, we start using summarize() to build a
table of descriptive statistics…
experiment %>% summarize(
Dataframe name
40. Descriptive Statistics
! Let’s try getting the mean of the RT column
! We start with our experiment dataframe…
! …then, we start using summarize() to build a
table of descriptive statistics…
! ..and, in particular, let’s get the mean() of the
RT column
experiment %>% summarize(MyMean=mean(RT))
Dataframe name Name of the column in
the resulting table (can
be whatever you want)
Descriptive
function Variable of
interest
41. Week 2.1: Descriptive Statistics in R
! R commands & functions
! Tidyverse & the Pipe Operator
! Multiple Functions
! Reading in data
! Saving R scripts
! Descriptive statistics
! 1 variable
! 2 variable
! Grouping
! Plotting
! Scatterplot
! Bar graph
42. Descriptive Statistics: 2 Variables
! Wow! That was complicated!
! But, once we have learned this general
format, we can easily make more complex
tables…
! Adds the SD (standard deviation) as a second
column
! Other relevant functions: median(), min(), max()
experiment %>% summarize(MyMean=mean(RT),
MySD=sd(RT))
44. Week 2.1: Descriptive Statistics in R
! R commands & functions
! Tidyverse & the Pipe Operator
! Multiple Functions
! Reading in data
! Saving R scripts
! Descriptive statistics
! 1 variable
! 2 variable
! Grouping
! Plotting
! Scatterplot
! Bar graph
45. Descriptive Statistics: Grouping
! We often want to look at a dependent variable
as a function of some independent variable(s)
! e.g., RTs for Plausible vs. Implausible sentences
! We add an intermediate step – the group_by()
function
- experiment %>% group_by(Condition)
%>% summarize(M=mean(RT))
- “Group the data by Condition, then get the mean
RT”
46. Descriptive Statistics: Grouping
! We often want to look at a dependent variable
as a function of some independent variable(s)
! We add an intermediate step – the group_by()
function
! Can even group by 2 or more variables:
! experiment %>% group_by(Subject, Condition)
%>% summarize(M=mean(RT))
! Each subject’s mean RT in each condition
47. Descriptive Statistics: Grouping
! We often want to look at a dependent variable
as a function of some independent variable(s)
! We add an intermediate step – the group_by()
function
! Can even group by 2 or more variables:
! experiment %>% group_by(Subject, Condition)
%>% summarize(M=mean(RT))
! Generic version of this:
! dataframe.name %>%
group_by(IndependentVar1, IndependentVar2)
%>% summarize(TableHeader=
function(DependentVar))
48. Descriptive Statistics: Grouping
! With group_by() and the n() function, we
can create contingency tables for
categorical variables:
- experiment %>% group_by(Subject, Condition)
%>% summarize(Observations=n())
Now, we are not getting the mean of any particular
dependent variable
We just want a frequency count of the number of
observations for each subject in each condition
49. Week 2.1: Descriptive Statistics in R
! R commands & functions
! Tidyverse & the Pipe Operator
! Multiple Functions
! Reading in data
! Saving R scripts
! Descriptive statistics
! 1 variable
! 2 variable
! Grouping
! Plotting
! Scatterplot
! Bar graph
50. Plotting
! Tidyverse also includes a function
for creating plots: ggplot()
! Each ggplot consists of two main elements:
! Mapping the variables onto one or more aesthetic
elements in your plot (e.g., X and Y axes, color,
line type)
51. Plotting
! Tidyverse also includes a function
for creating plots: ggplot()
! Each ggplot consists of two main elements:
! Mapping the variables onto one or more aesthetic
elements in your plot (e.g., X and Y axes, color,
line type)
52. Plotting
! Tidyverse also includes a function
for creating plots: ggplot()
! Each ggplot consists of two main elements:
! Mapping the variables onto one or more aesthetic
elements in your plot (e.g., X and Y axes, color,
line type)
53. Plotting
! Tidyverse also includes a function
for creating plots: ggplot()
! Each ggplot consists of two main elements:
! Mapping the variables onto one or more aesthetic
elements in your plot (e.g., X and Y axes, color,
line type)
Day
Partner
Warmth
54. Plotting
! Tidyverse also includes a function
for creating plots: ggplot()
! Each ggplot consists of two main elements:
! Mapping the variables onto one or more aesthetic
elements in your plot (e.g., X and Y axes, color,
line type)
! Adding one or more visual elements (geoms) to
depict each observation (e.g., points, bars, lines)
55. Plotting: Scatterplot
! Does RT change over the course of the
experiment?
! Basic scatterplot:
! experiment %>%
ggplot(aes(x=TrialsRemaining, y=RT)) +
geom_point()
Here, we are saying how we want to
translate the variables into visual form:
the X axis will represent
TrialsRemaining, and the Y axis will
represent the RT variable
Then, we want to represent each
observation with a point
58. Plotting: Scatterplot
! We can add additional variables into the plot
by specifying what aesthetic element they
should be mapped to:
! experiment %>%
ggplot(aes(x=TrialsRemaining, y=RT,
color=Condition)) + geom_point()
! Now, we represent the Condition variable with
the color of each point
60. Week 2.1: Descriptive Statistics in R
! R commands & functions
! Tidyverse & the Pipe Operator
! Multiple Functions
! Reading in data
! Saving R scripts
! Descriptive statistics
! 1 variable
! 2 variable
! Grouping
! Plotting
! Scatterplot
! Bar graph
61. Plotting: Bar Graph
! Now let’s make a bar graph to compare
conditions
! KEY POINT: A bar graph displays means--
that is, summarized data
! Thus, we first need to compute those means
62. Plotting: Bar Graph
! Now let’s make a bar graph to compare
conditions
! KEY POINT: A bar graph displays means--
that is, summarized data
! Thus, we first need to compute those means
63. Plotting: Bar Graph
! Now let’s make a bar graph to compare
conditions
! experiment %>%
group_by(Condition) %>%
summarize(MeanRT=mean(RT)) %>%
ggplot(aes(x=Condition, fill=Condition,
y=MeanRT)) +
geom_col()
Here, we are
grouping by
Condition and getting
the mean RT in each
condition
The x-axis and bar color
will represent Condition
The y-axis (bar height)
will represent MeanRT
geom_col() for
bar graphs