Articles by John Quick

Singleton Remover CSV v0.3

April 21, 2014 | John Quick

I created a small program called Singleton Remover CSV to help researchers process files quickly that might otherwise take a long time to be handled by hand. The program simply compares ID values given in the first two columns of a .csv file, saves any...

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R Tutorial Series: Centering Variables and Generating Z-Scores with the Scale() Function

March 1, 2012 | John Quick

Centering variables and creating z-scores are two common data analysis activities. While they are relatively simple to calculate by hand, R makes these operations extremely easy thanks to the scale() function. Tutorial FilesBefore we begin, you may wan... [Read more...]

R Tutorial Series: Citing R with EndNote

January 6, 2012 | John Quick

Unfortunately, due to the vexing complexities of academic style guides and the limitations of associated software packages, citing a non-standard name, such as Cher, Prince, or R Development Core Team can be problematic. Thankfully, I have discovered a... [Read more...]

R Tutorial Series: Exploratory Factor Analysis

October 24, 2011 | John Quick

Exploratory factor analysis (EFA) is a common technique in the social sciences for explaining the variance between several measured variables as a smaller set of latent variables. EFA is often used to consolidate survey data by revealing the groupings ... [Read more...]

The R Programming Wikibook

July 8, 2011 | John Quick

The R Programming wikibook is an open source community project that "aims to create a cross-disciplinary practical guide to the R programming language." It was launched in June 2011 and is seeking content and contributors. The full call for the R Progr...

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R Tutorial Series: 2011 ANOVA Article Data

March 28, 2011 | John Quick

Having wrapped up a recent flurry of R ANOVA articles (and exhausted my knowledge of the subject), I decided to take a look at the R Tutorial Series' Google Analytics data from the past few months. Since I posted the Two-Way Omnibus ANOVA article on J... [Read more...]

R Tutorial Series: Applying the Reshape Package to Organize ANOVA Data

March 14, 2011 | John Quick

As demonstrated in the preceding ANOVA tutorials, data organization is central to conducting ANOVA in R. In standard ANOVA, we used the tapply() function to generate a table for a single summary function. In repeated measures ANOVA, we used separate da... [Read more...]

R Tutorial Series: ANOVA Pairwise Comparison Methods

March 7, 2011 | John Quick

When we have a statistically significant effect in ANOVA and an independent variable of more than two levels, we typically want to make follow-up comparisons. There are numerous methods for making pairwise comparisons and this tutorial will demonstrate... [Read more...]

R Tutorial Series: Two-Way ANOVA with Unequal Sample Sizes

February 28, 2011 | John Quick

When the sample sizes within the levels of our independent variables are not equal, we have to handle our ANOVA differently than in the typical two-way case. This tutorial will demonstrate how to conduct a two-way ANOVA in R when the sample sizes withi... [Read more...]

R Tutorial Series: Two-Way Repeated Measures ANOVA

February 21, 2011 | John Quick

Repeated measures data require a different analysis procedure than our typical two-way ANOVA and subsequently follow a different R process. This tutorial will demonstrate how to conduct two-way repeated measures ANOVA in R using the Anova() function fr... [Read more...]

Book Review: R Graphs Cookbook

February 17, 2011 | John Quick

Book InformationMittal, H. (2011). R graphs cookbook. Birmingham, UK: Packt Publishing Ltd.AudienceThe book's stated audience is anyone who is familiar with the basics of R, as well as expert users who are looking for a graphical reference. However, it...

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R Tutorial Series: One-Way Repeated Measures ANOVA

February 14, 2011 | John Quick

Repeated measures data require a different analysis procedure than our typical one-way ANOVA and subsequently follow a different R process. This tutorial will demonstrate how to conduct one-way repeated measures ANOVA in R using the Anova(mod, idata, i... [Read more...]

R Tutorial Series: Two-Way ANOVA with Interactions and Simple Main Effects

February 7, 2011 | John Quick

When an interaction is present in a two-way ANOVA, we typically choose to ignore the main effects and elect to investigate the simple main effects when making pairwise comparisons. This tutorial will demonstrate how to conduct pairwise comparisons when... [Read more...]

Statistical Analysis with R Book Reviews

February 2, 2011 | John Quick

Reviews of my Statistical Analysis with R book have started to emerge online and I am writing today to share them with potential readers and recommenders. Reviews The following is a list of online reviews for Statistical Analysis with R. If you have w... [Read more...]

R Tutorial Series: One-Way ANOVA with Pairwise Comparisons

January 24, 2011 | John Quick

When we have more than two groups in a one-way ANOVA, we typically want to statistically assess the differences between each group. Whereas a one-way omnibus ANOVA assesses whether a significant difference exists at all amongst the groups, pairwise com... [Read more...]

R Tutorial Series: Two-Way Omnibus ANOVA

January 17, 2011 | John Quick

As with the one-way case, testing the omnibus hypothesis via two-way ANOVA is simple process in R. This tutorial will explore how R can be used to perform a two-way ANOVA to test the difference between two (or more) group means. Tutorial FilesBefore we... [Read more...]

R Beginner’s Guide Book Update: Statistical Analysis with R Released

November 8, 2010 | John Quick

In the final days of October, my beginner's guide to R was released. The book's official title is Statistical Analysis with R and it can be found on the Packt Publishing website. The primary focus of Statistical Analysis with R is helping new users bec... [Read more...]

R Tutorial Series: One-Way Omnibus ANOVA

October 11, 2010 | John Quick

Testing the omnibus hypothesis via one-way ANOVA is simple process in R. This tutorial will explore how R can be used to perform a one-way ANOVA to test the difference between two (or more) group means. Tutorial FilesBefore we begin, you may want to do... [Read more...]

R Beginner’s Guide Book Update 10/1/2010

October 1, 2010 | John Quick

Update: Statistical Analysis with R is now available!I recently submitted the final drafts of all chapters of my R Beginner's Guide book, which is to be published through Packt. The official publishing timeline is set to December 2010, although the boo...

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R Tutorial Series: Labeling Data Points on a Plot

September 19, 2010 | John Quick

There are times that labeling a plot's data points can be very useful, such as when conveying information in certain visuals or looking for patterns in our data. Fortunately, labeling the individual data points on a plot is a relatively simple process ... [Read more...]

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Articles by John Quick

Singleton Remover CSV v0.3

R Tutorial Series: Centering Variables and Generating Z-Scores with the Scale() Function

R Tutorial Series: Citing R with EndNote

R Tutorial Series: Exploratory Factor Analysis

The R Programming Wikibook

R Tutorial Series: 2011 ANOVA Article Data

R Tutorial Series: Applying the Reshape Package to Organize ANOVA Data

R Tutorial Series: ANOVA Pairwise Comparison Methods

R Tutorial Series: Two-Way ANOVA with Unequal Sample Sizes

R Tutorial Series: Two-Way Repeated Measures ANOVA

Book Review: R Graphs Cookbook

R Tutorial Series: One-Way Repeated Measures ANOVA

R Tutorial Series: Two-Way ANOVA with Interactions and Simple Main Effects

Statistical Analysis with R Book Reviews

R Tutorial Series: One-Way ANOVA with Pairwise Comparisons

R Tutorial Series: Two-Way Omnibus ANOVA

R Beginner’s Guide Book Update: Statistical Analysis with R Released

R Tutorial Series: One-Way Omnibus ANOVA

R Beginner’s Guide Book Update 10/1/2010

R Tutorial Series: Labeling Data Points on a Plot

Articles by John Quick

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