# Posts Tagged ‘ ANOVA ’

## Study design – test power, test rejection rate, permutation test

August 16, 2013
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In an experiment involving social policy, a question has arisen as to what statistical method to use. The outcome is 0/1 -- let's say, whether a criminal defendant shows up for trial or not. Then there are a control group and 4 treatment groups (thus, ...

## Some Common Approaches for Analyzing Likert Scales and Other Categorical Data

July 2, 2013
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$Some Common Approaches for Analyzing Likert Scales and Other Categorical Data$

Analyzing Likert scale responses really comes down to what you want to accomplish (e.g. Are you trying to provide a formal report with probabilities or are you trying to simply understand the data better). Sometimes a couple of graphs are sufficient and a formalize statistical test isn’t even necessary. However, with how easy it is […]

June 13, 2013
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## Neuroscience, statistical power and how to increase it

April 21, 2013
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There has been quite a bit of buzz recently about the Button et al. Nature Reviews Neuroscience paper on statistical power. Several similar reviews have been published in psychology and other disciplines and come to broadly the same conclusion - that m...

## 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 […]

## Analyzing Pre-Post Data with Repeated Measures or ANCOVA

January 22, 2013
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This kind of situation happens all the time, in which a colleague, a reviewer, or a statistical consultant insists that you need to do the analysis differently. Sometimes they're right, but sometimes, as was true here, the two analyses answer different research questions.

## Confusing Statistical Term #7: GLM

August 9, 2012
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Like some of the other terms in our list--level and beta--GLM has two different meanings. It's a little different than the others, though, because it's an abbreviation for two different terms: General Linear Model and Generalized Linear Model. It's extra confusing because their names are so similar on top of having the same abbreviation.

## Serious stats book officially published

July 5, 2012
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My serious stats book is officially published (in the UK at least). The US release date is next month (August 7th). I'm not sure why the release is later (possibly extra shipping time for the books). The earlier European release date is I suppose compe...

## 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 […]

## The stimuli-as-fixed-effect fallacy

June 21, 2012
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Neuroskeptic has just blogged on a new paper by Judd, Westfall and Kenny on Treating stimuli as a random factor in social psychology: A new and comprehensive solution to a pervasive but largely ignored problem. I can't access the original pap...