# Running ANCOVA with categorical covariates - how to set up dataset?

I am analyzing a dataset in which 80 participants rated 4 products (product A, product B, product C, product D) from -3 to 3 depending on how much they liked the product. Each participant provided categorical demographic information such as gender, ethnicity, age group, and employment status.

I would like to run an ANCOVA with the product type as the IV, the rating number as the DV, and all of the demographic variables as categorical covariates.

Should my dataset have 320 rows with the following columns: Product, Rating, Gender, Ethnicity, AgeGroup, EmploymentStatus? Each participant would have 4 rows such that there is a row for their product A, B, C, and D rating. I would repeat their demographic data for each row. Or should I set up my data differently?

Additionally, I plan to use SPSS and dummy code each of the categorical covariates with C-1 groups and input these categorical covariates in the "Covariate" box and not the "Fixed Factors" box in the Analyze - Univariate - GLM tool. Would this be the right way to go about this?

Thank you kindly for any advice!

• What is your research question ? Are your covariates balanced ? Nov 11 '20 at 10:33
• Thank you for your time, Robert. My research question is - is there a difference in the mean ratings for each product (i.e. do people prefer for any of the products more than the other products). Regarding balanced covariates - I'm not exactly sure what this means, but each person provided ratings for all 4 products and there is very little missing data. The groups within each demographic categorical covariate are not equal (e.g. for ethnicity, there were more white participants than asian participants). Hope this helps clarify. Nov 11 '20 at 16:15

rating ~ product + covariates