中介效应sobel检验——sgmediation.zip

<pre> ------------------------------------------------------------------------------- help for <b>sgmediation</b> ------------------------------------------------------------------------------- <p> <b><u>Sobel-Goodman mediation tests</u></b> <p> <b>sgmediation</b> <i>depvar</i> [<b>if</b> <i>exp</i>] [<b>in</b> <i>range</i>] <b>,</b> <b>mv(</b><i>mediatorvar</i><b>)</b> <b>iv(</b><i>indvar</i><b>)</b> [ <b>cv(</b><i>covarlist</i><b>)</b> <b><u>boot</u></b><b>strap</b> <b>reps(</b><i># reps</i><b>)</b> <b>level(</b><i>#</i><b>)</b> ] <p> <b><u>Description</u></b> <p> The purpose of the Sobel-Goodman tests are to test whether a mediator carries the influence of an IV to a DV. <p> A variable may be considered a mediator to the extent to which it carries the influence of a given independent variable (IV) to a given dependent variable (DV). Generally speaking, mediation can be said to occur when (1) the IV significantly affects the mediator, (2) the IV significantly affects the DV in the absence of the mediator, (3) the mediator has a significant unique effect on the DV, and (4) the effect of the IV on the DV shrinks upon the addition of the mediator to the model. More formally, the Sobel-Goodman tests are statistically based methods by which mediation may be assessed. <p> <b><u>Options</u></b> <b>cv(</b><i>covarlist</i><b>)</b> Optional list of covariate variables. <b>bootstrap</b> Computes percentile and bias-corrected bootstrap confidence intervals. <b>reps(</b><i>#</i><b>)</b> Number of replications for bootstrap. The default is 200. <b>level(</b><i>#</i><b>)</b> Confidence level for bootstrap. The default is 95%. <p> <b><u>Examples</u></b> <p> <b>. sgmediation write, mv(ses) iv(read)</b> <b>. sgmediation write, mv(ses) iv(read) bootstrap</b> <b>. sgmediation write, mv(ses) iv(read) cv(black hispanic) bootstrap</b> <b>reps(500) level(99)</b> <p> <b><u>References</u></b> <p> MacKinnon, D. P., &amp; Dwyer, J. H. (1993). Estimating mediated effects in prevention studies.<i> Evaluation Review</i>,<i> 17</i>, 144-158. MacKinnon, D. P., Warsi, G., &amp; Dwyer, J. H. (1995). A simulation study of mediated effect measures. <i>Multivariate Behavioral Research</i>, <i>30</i>(1), 41-62. Preacher, K. J., &amp; Hayes, A. F. (2004). SPSS and SAS procedures for estimating indirect effects in simple mediation models. <i>Behavior</i> <i>Research Methods, Instruments, &amp; Computers</i>, <i>36</i>(4), 717-731. </pre>