I'm looking for some help with data analysis. Briefly, here is the experimental design. My student wanted to know if the appearance of a recycling container would affect the likelihood that a person would place a recyclable bottle in that container. So, she designed two types of containers (experimental and control) and placed them in 46 classrooms in a nearby high school (21 control and 25 expt -- a few control rooms became unavailable as the experiment progressed). For 6 weeks she has counted the number of bottles in each room.
I had intended to compare the effect of these two treatments over time with a Repeated Measures ANOVA. Unfortunately, none of the data transformations I've tried will normalize the data, so I've settled on Friedman's test as the nonparametric alternative to RM ANOVA. However, I'm having trouble convincing my SPSS software to compare expt with control groups. It seems only to compare the repeated measures (weeks) x location (room). Any suggestions on how to perform the analysis to compare the effect of the type of container would be appreciated! We will next swap containers for 6 weeks, so that each room will have experienced both types of containers. Suggestions on how to add this to the analysis would also be appreciated. Cheers, Joe Poston Salisbury, NC USA
