2.50
Hdl Handle:
http://hdl.handle.net/10755/165988
Category:
Abstract
Type:
Presentation
Title:
Testing and interpreting moderator effects
Author(s):
Belyea, Michael J.
Author Details:
Michael Belyea, , University of North Carolina at Chapel Hill School of Nursing, Chapel Hill, North Carolina, USA, email: mbelyea@email.unc.edu
Abstract:
In testing the efficacy of an intervention, many theories posit that one independent variable moderates the relationship between the dependent variable and another independent variable. The common way of testing for moderators is to look at whether or not two independent variables interact in such a way that the effect of either one on the dependent variable depends on the level of the other variable. While statistical tests for interactions between categorical variables are well known, testing interactions or moderator effects for continuous variables are less well known and under utilized. In this presentation the modern approach to testing and interpreting moderator effects for continuous variables will be demonstrated. Interactions will be created as product term interactions and all variables involved will be centered (i.e., subtracted from their means) to facilitate interpretation and reduce potential problems with multicollinearity. Examples from several longitudinal intervention studies will be used to illustrate key points, where interaction terms will be added to a general linear model containing terms for the intervention group and time to see if they affect the study's outcomes. Plotting and post-hoc tests of the individual plotted lines will be used to facilitate interpretation. Finally, methodological issues in detecting moderator effects and the implications for experimental and description studies will be discussed.
Repository Posting Date:
27-Oct-2011
Date of Publication:
27-Oct-2011
Conference Host:
Southern Nursing Research Society
Note:
This is an abstract-only submission. If the author has submitted a full-text item based on this abstract, you may find it by browsing the Virginia Henderson Global Nursing e-Repository by author. If author contact information is available in this abstract, please feel free to contact him or her with your queries regarding this submission. Alternatively, please contact the conference host, journal, or publisher (according to the circumstance) for further details regarding this item. If a citation is listed in this record, the item has been published and is available via open-access avenues or a journal/database subscription. Contact your library for assistance in obtaining the as-published article.

Full metadata record

DC FieldValue Language
dc.type.categoryAbstracten_US
dc.typePresentationen_GB
dc.titleTesting and interpreting moderator effectsen_GB
dc.contributor.authorBelyea, Michael J.en_US
dc.author.detailsMichael Belyea, , University of North Carolina at Chapel Hill School of Nursing, Chapel Hill, North Carolina, USA, email: mbelyea@email.unc.eduen_US
dc.identifier.urihttp://hdl.handle.net/10755/165988-
dc.description.abstractIn testing the efficacy of an intervention, many theories posit that one independent variable moderates the relationship between the dependent variable and another independent variable. The common way of testing for moderators is to look at whether or not two independent variables interact in such a way that the effect of either one on the dependent variable depends on the level of the other variable. While statistical tests for interactions between categorical variables are well known, testing interactions or moderator effects for continuous variables are less well known and under utilized. In this presentation the modern approach to testing and interpreting moderator effects for continuous variables will be demonstrated. Interactions will be created as product term interactions and all variables involved will be centered (i.e., subtracted from their means) to facilitate interpretation and reduce potential problems with multicollinearity. Examples from several longitudinal intervention studies will be used to illustrate key points, where interaction terms will be added to a general linear model containing terms for the intervention group and time to see if they affect the study's outcomes. Plotting and post-hoc tests of the individual plotted lines will be used to facilitate interpretation. Finally, methodological issues in detecting moderator effects and the implications for experimental and description studies will be discussed.en_GB
dc.date.available2011-10-27T14:37:55Z-
dc.date.issued2011-10-27en_GB
dc.date.accessioned2011-10-27T14:37:55Z-
dc.conference.hostSouthern Nursing Research Societyen_US
dc.description.noteThis is an abstract-only submission. If the author has submitted a full-text item based on this abstract, you may find it by browsing the Virginia Henderson Global Nursing e-Repository by author. If author contact information is available in this abstract, please feel free to contact him or her with your queries regarding this submission. Alternatively, please contact the conference host, journal, or publisher (according to the circumstance) for further details regarding this item. If a citation is listed in this record, the item has been published and is available via open-access avenues or a journal/database subscription. Contact your library for assistance in obtaining the as-published article.-
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