PSYCHOLOGY 301
Methods & Design in Psychology

Lecture 6 (2005)

Multiple Linear Regression 2

 

Readings

      Multivariate Techniques (Weiss)
(optional, but the section on MLR is recommended)

 

Overview of MLR2 Lecture

      Types of MLR (from MLR Lecture 1)

      General MLR strategy

 

General MLR Strategy

         Check assumptions

         Conduct MLR choose type

         Interpret the output

         Develop a regression equation

 

1. Check Assumptions

             Check histograms of all variables

             Check scatterplots

             Check correlation table

             Check influential outlying cases

 

2. Conduct a Multiple Linear Regression

Conduct a multiple linear regression:

         Standard

         Hierarchical

         Stepwise

         Forward

         Backward

 

3. Interpret the results

Interpret the technical and psychological meaning of the results, based on:

             R, R2, Adjusted R2, the statistical significance of R

             Changes in R and the significance of the changes if steps (i.e., more than 1 model are used)

             Standardised and unstandardised regression coefficients for each model

             Zero-order and partial correlations for each IV in each model

 

4. Regression equation

If useful, develop a regression equation for the final model.