# 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, R*2, Adjusted *R*2, 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.