A Repeated Measures Analysis of Variance

A fast food chain plans to add a new item to its menu. However, they are still undecided between three possible campaigns for promoting the new product. In order to determine which promotion has the greatest effect on sales, the new item is introduced at locations in several test markets. A different promotion is used at each store location, and the weekly sales of the new item are recorded for the first four weeks.

This information is collected in testmarket.sav. See the topic Sample Files for more information. Use the GLM Repeated Measures procedure to measure the effect of each promotion on sales, while accounting for the within-subjects effect of Week.

Because the data file was originally set up for analysis in the Linear Mixed Models procedure, you need to restructure the file from cases to variables.

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