Researchers at Purdue University conducted an experiment to compare three methods of teaching reading. Students were randomly assigned to one of the three teaching methods, and their reading comprehension was tested before and after they received the instruction. Several different measures of reading comprehension, from both the pre- and posttests are included in the dataset.
All of the test score variables appear normally distributed. Simple ANOVA models using teaching method as the independent variable and each of the test scores as a dependent variable may be used to detect differences among teaching methods. When the pretest scores are used as dependent variables, the F-tests are not significant. This is appropriate because the students were randomly assigned to the groups. The F-tests are significant for all three models with a post-test score as dependent variable.