ANOVA

http://www.gardenersown.co.uk/Education/Lectures/R/anova.htm#anova

http://www.personality-project.org/r/r.anova.html

A special case of the linear model is the situation where the predictor variables are categorical. In psychological research this usually reflects experimental design where the independent variables are multiple levels of some experimental manipulation (e.g., drug administration, recall instructions, etc.)

The first 5 examples are adapted from the guide to S+ developed by TAs for Roger Ratcliff. For more detail on data entry consult that guide. The last three examples discuss how to reorganize the data from a standard data frame into one appropriate for within subject analyses. For this discussion, I assume that appropriate data files have been created in a text editor and saved in a subjects x variables table.