GRADUATE COURSES

Research Designs for Health Service Programs - PSY 224

UNDERGRADUATE COURSES

Positive Psychology - PSY 27

HELPFUL STATISTICS STUFF

Data Screening

Handout I created based on Tabachnick and Fidell (2007). (DOWNLOAD PDF)

Treating Missing Data

This is my favorite book on treating missing data.

 McKnight, P. E., McKnight, K. M., Sidani, S., & Figueredo, A. J. (2007). Missing data: A gentle introduction. New York : The Guildford Press.

Dr. David C. Howell clearly, and succinctly, describes treating missing data.

http://www.uvm.edu/~dhowell/StatPages/More_Stuff/Missing_Data/Missing.html

 

Here’s a link to MICE (Multivariate Imputation by Chained Equations), a free and wonderful program for multiple imputation:

http://web.inter.nl.net/users/S.van.Buuren/mi/hmtl/mice.htm

This is a fantastic resource from the Penn State Population Research Institute Statistics Core for understanding and treating missing data.

http://help.pop.psu.edu/help-by-statistical-method/missing-data-imputation

Multiple Imputation for Missing Data: What Is It And How Can I Use It? by Jeffrey Wayman (DOWNLOAD PDF)

Creating Dummy Codes

This clearly describes how to create dummy codes. My students find it helpful.

 
http://www.gseis.ucla.edu/courses/ed230b/cmptrlab/spsshw4c.htm

Mediation and Moderation (essential for discovering complex processes)

1. This is a classic article on moderation and mediation.

Baron, R. M., & Kenny, D. A. (1986). The moderator-mediator variable distinction in social psychological research: Conceptual, strategic, and statistical considerations. Journal of Personality and Social Psychology, 51, 1173 - 1182. (DOWNLOAD PDF)


2. Here's the link to Dr. David A. Kenny's homepage. It's an incredible resource for mediation, moderation, SEM, and a ton of other cool things. If you're looking for a clear and concise explanation of mediation and moderation, search no more. This is it.
http://davidakenny.net/kenny.htm
 

3. Here's the link to Dr. Kristopher J. Preacher's webpage for quantpsy. It's chock full of resources for helping people analyze mediators and moderators. Here you'll find cool things such as interactive calculators for the Sobel test for simple mediation effects and simple slopes and the region of significance for interactions.
http://www.people.ku.edu/~preacher/

 

4. Here's a guide I created for using SPSS script for estimating indirect effects in simple and multiple mediation models with and without covariates. The script allows you to examine mediation with bootstrapping. (DOWNLOAD WORD DOCUMENT)

5. Here are three Excel files to help you plot 2-way interactions when you probe them with the pick-a-point approach.

Continuous IV and Binary Moderator: (DOWNLOAD EXCEL FILE)

NOTE: The chart below was used for a study where gratitude was a covariate (see GAC1 in row 3). To use this chart WITHOUT a covariate, simply put the value of 0 for the regression coefficient of this control variable. So, here you would put "0" in the cell B3. Don't worry about changing anything for the Mean or SD of this variable because with a zero regression weight they don't add to the prediction of implied scores of the DV.

Binary IV and Continuous Moderator: (DOWNLOAD EXCEL FILE)

Continuous IV and Continuous Moderator: (DOWNLOAD EXCEL FILE)

6. Here’s a fabulous website by Dr. James Dawson that explains how to interpret interaction effects and provides several Excel spreadsheets to plot the interactions. http://www.jeremydawson.co.uk/slopes.htm

7. Here’s a guide I created for using SPSS script for probing interactions in OLS and logistic regression. It focuses on the Johnson-Neyman technique. (DOWNLOAD WORD DOCUMENT)

Miscellaneous

1. Here's an Excel chart for comparing correlation coefficents for independent and dependent samples. (DOWNLOAD EXCEL FILE)