ebooks logo journals logo reference works logo abstract databases logo
bullet  SIGN IN Register | Why Register? | Got a Voucher? alerts   marked lists   shopping cart 

informaworld

HOME   |   SEARCH   |   BROWSE
    Issues List       Latest Issue       Volume 15 Issue 1       Subscribe       Article       References       Cited By       Related articles      
<< firstfirst   < prevprev   Table of contentstoc   next >next   last >>last
Publisher Logo Publication Cover
Search within this journal

Resampling and Distribution of the Product Methods for Testing Indirect Effects in Complex Models 

Authors: Jason Williams a; David P. MacKinnon b
Affiliations:   a RTI International,
b Department of Psychology, Arizona State University,
DOI: 10.1080/10705510701758166
Publication Frequency: 4 issues per year
Published in: journal Structural Equation Modeling: A Multidisciplinary Journal, Volume 15, Issue 1 January 2008 , pages 23 - 51
Formats available: HTML (English) : PDF (English)
Article Requests: Order Reprints : Request Permissions


Abstract

Recent advances in testing mediation have found that certain resampling methods and tests based on the mathematical distribution of 2 normal random variables substantially outperform the traditional z test. However, these studies have primarily focused only on models with a single mediator and 2 component paths. To address this limitation, a simulation was conducted to evaluate these alternative methods in a more complex path model with multiple mediators and indirect paths with 2 and 3 paths. Methods for testing contrasts of 2 effects were evaluated also. The simulation included 1 exogenous independent variable, 3 mediators and 2 outcomes and varied sample size, number of paths in the mediated effects, test used to evaluate effects, effect sizes for each path, and the value of the contrast. Confidence intervals were used to evaluate the power and Type I error rate of each method, and were examined for coverage and bias. The bias-corrected bootstrap had the least biased confidence intervals, greatest power to detect nonzero effects and contrasts, and the most accurate overall Type I error. All tests had less power to detect 3-path effects and more inaccurate Type I error compared to 2-path effects. Confidence intervals were biased for mediated effects, as found in previous studies. Results for contrasts did not vary greatly by test, although resampling approaches had somewhat greater power and might be preferable because of ease of use and flexibility.
view references (36) : view citations
Bookmark with:
  • CiteULike
  • Del.icio.us
  • BibSonomy
  • Connotea
  • More bookmarks
Privacy Policy | Terms & Conditions | Accessibility | RSS
FAQs in: English . Français . Español . 中文(简体和繁體)
© 2009 Informa plc