Blog Archives

Using multilevel models to get accurate inferences for repeated measures ANOVA designs

April 18, 2013
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It is now increasingly common for experimental psychologists (among others) to use multilevel models (also known as linear mixed models) to analyze data that used to be shoe-horned into a repeated measures ANOVA design. Chapter 18 of Serious Stats introduces multilevel models by considering them as an extension of repeated measures ANOVA models that can

Using multilevel models to get accurate inferences for repeated measures ANOVA designs

April 18, 2013
By

It is now increasingly common for experimental psychologists (among others) to use multilevel models (also known as linear mixed models) to analyze data that used to be shoe-horned into a repeated measures ANOVA design. Chapter 18 of Serious Stats introduces multilevel models by considering them as an extension of repeated measures ANOVA models that can

Near-instant high quality graphs in R

September 5, 2012
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One of the main attractions of R (for me) is the ability to produce high quality graphics that look just the way you want them to. The basic plot functions are generally excellent for exploratory work and for getting to know your data. Most packages have additional functions for appropriate exploratory work or for summarizing

Near-instant high quality graphs in R

September 5, 2012
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One of the main attractions of R (for me) is the ability to produce high quality graphics that look just the way you want them to. The basic plot functions are generally excellent for exploratory work and for getting to know your data. Most packages have additional functions for appropriate exploratory work or for summarizing

Confidence intervals with tiers: functions for between-subjects (independent measures) ANOVA

June 21, 2012
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In a previous post I showed how to plot difference-adjusted CIs for between-subjects (independent measures) ANOVA designs (see here). The rationale behind this kind of graphical display is introduced in Chapter 3 of Serious stats (and summarized in my earlier blog post). In a between-subjects – or in indeed in a within-subjects (repeated measures) – design

Pasting Excel data into R on a Mac

June 2, 2012
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When starting out with R, getting data in and out can be a bit of a pain. It should take long to work out a convenient method – depending on what OS you use and what other packages you work with. In my case I prefer to work with Excel spreadsheets (which are versatile and

Updating to R 2.15, warnings in R and an updated function list for Serious Stats

May 27, 2012
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Whilst writing the book  the latest version of R changed several times. Although I started on an earlier version, the bulk of the book was written with 2.11 and it was finished under R 2.12. The final version of the R scripts were therefore run and checked using R 2.12 and, in the main, the most recent

R functions for serious stats

March 25, 2012
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UPDATE: Some problems arose with my previous host so I have now updated the links here and elsewhere on the blog. The companion web site for Serious Stats has a zip file with R scripts for each chapter. This contains examples of R code and and all my functions from the book (and a few extras).

Serious stats companion web site now live: sample chapter, data and R scripts

March 23, 2012
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The companion web site for Serious stats is now live: http://www.palgrave.com/psychology/Baguley/ It includes a sample chapter (Chapter 15: Contrasts), data sets, R scripts for all the examples and supplementary material. Filed under: news, R code, ser...

Independent measures (between-subjects) ANOVA and displaying confidence intervals for differences in means

March 18, 2012
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$Independent measures (between-subjects) ANOVA and displaying confidence intervals for differences in means$

In Chapter 2 (Confidence Intervals) of Serious stats I consider the problem of displaying confidence intervals (CIs) of a set of means (which I illustrate with the simple case of two independent means). Later, in Chapter 16 (Repeated Measures ANOVA), I consider the trickier problem of displaying of two or more means from paired or