[StATS]: Moderator variables (February 15, 2005).
I’ve always disliked the excessive use of detailed terminology, but when someone asked me about moderator variables, I had to look up the details. Basically, a moderator variable is one that interacts with the exposure or treatment variable. It effectively forces you to qualify your findings. Here’s a published example with abstract (I have not read the full article):
- The relation between locus of control and coping in two contexts: age as a moderator variable. Blanchard-Fields F, Irion JC. Psychol Aging 1988: 3(2); 197-203. [Medline] We examined the relation between locus of control and coping as moderated by age and context. A total of 96 adolescents, young adults, middle-aged adults, and older adults were administered Lazarus’s Ways of Coping questionnaire, a situation-specific controllability measure, a defensive coping questionnaire, and Levenson’s Internality, Powerfulness of Others, and Chance global locus of control scales for challenging and threatening contexts. Age moderated the relation between locus of control and coping. Internality was positively related to escape-avoidance, hostile reaction, and self-blame for younger individuals and negatively related for older adults. A belief in powerfulness of others was positively related to planful problem-solving and self-controlling in older adults and negatively related for younger individuals. Finally, a belief in chance was positively related to distancing and self-controlling for older adults and negatively related for younger individuals. The implication that dimensions of control vary with age is discussed.
As you can see, the relationship between locus of control and coping is quite different for younger individuals compared to older individuals.
Some web resources that offer definitions of moderator variables are:
- www.eiu.edu/~lhelsel/tec5143/activities/variables.pdf
- www.gseis.ucla.edu/courses/ed230a2/mediator.html
- mailhost.sfb504.uni-mannheim.de/glossary/moderat.htm
- psych.wisc.edu/henriques/mediator.html
- www.psych.ubc.ca/~schaller/Baron1986.pdf
There are additional terms used in the research literature such as mediator variable and intervening variable. I generally try to avoid using these terms, and even shy away from the commonly used term “confounding variable.”
This page was written by Steve Simon while working at Children’s Mercy Hospital. Although I do not hold the copyright for this material, I am reproducing it here as a service, as it is no longer available on the Children’s Mercy Hospital website. Need more information? I have a page with general help resources. You can also browse for pages similar to this one at Category: Covariate adjustment.
adjustment](../category/CovariateAdjustment.html). for pages similar to this one at [Category: Covariate with general help resources. You can also browse Children’s Mercy Hospital website. Need more information? I have a page reproducing it here as a service, as it is no longer available on the Hospital. Although I do not hold the copyright for this material, I am This page was written by Steve Simon while working at Children’s Mercy