Moderation

This week is about using regression for testing moderation hypotheses as well as curvilinear hypotheses.

Primary readings

• Kenny, David. Handout on moderation [html]

• UCLA handout on curvilinear relationships [html]

• Spiller, S. A., Fitzsimons, G. J., Lynch Jr, J. G., & McClelland, G. H. (2013). Spotlights, floodlights, and the magic number zero: Simple effects tests in moderated regression. Journal of Marketing Research, 50(2), 277-288. [pdf]

Secondary readings

• Kromrey, J. D., & Foster-Johnson, L. (1998). Mean centering in moderated multiple regression: Much ado about nothing. Educational and Psychological Measurement, 58(1), 42-67. [^pdf]

Software tools

• PROCESS macro for SPSS and SAS

  • • Download latest from http://www.processmacro.org or use this (possibly old) zip file (zip)

    • Documentation:

      • Brief handout [html]

    • Hayes, A. F. (2013). Introduction to mediation, moderation, and conditional process analysis. New York: The Guilford Press. [web page]

• Jeremy Dawson's Excel sheets for testing interactions. [html]

• After installing PROCESS, we will working with gss2008 dataset. A few commands we will execute:

• • compute revhappy = 4 - happy

    • filter the cases to retain only sibs < 20 and income > 0 and income < 13

  • process vars=sex age sibs income childs revhappy/y=revhappy/x=childs/m=income/model=1/jn=1/quantile=1/plot=1.

Data

• • csv version of the gss2008 data [csv]