Child Development 133  Research Methods in Human Development Sections 04, 68, & 69 Hembree           Spring, 2011
 Instructor Schedule Resources Syllabus Assignments

I. Introduction - Design Issues

Design = Plan of Experiment ("blueprint")

1) How many variables to test?

2) How many levels for each variable?

3) How to compose groups?

II. (True) experimental design

A. Levels and variables

B. Simple, two-group design

•  experimental group

•   control group

C. Assignment of subjects

1. Random assignment

2. Correlated assignment

a. matched pair

b. natural pairs

c. repeated measures

E. Increasing the complexity of designs

1. Increase the number of levels of a variable

2. Increase the number of dependent variables

3. Increase the number of Independent Variables – Factorial Designs

III. Factorial Designs

• Increasing the complexity by increasing the number of Independent Variables

B. Main effects vs. interaction effects

MAIN EFFECTS – the effects of one variable, ignoring (averaged across) the other

INTERACTION EFFECTS – the effects of the variables together

Does one variable CHANGE the effects of another?

an example:...

Caffeine

Morning

Afternoon

None

2 cups

1. What are some hypotheses we could make?

2. Possible outcomes:

• Main Effects ONLY

• Interaction Effects

3. What would both main effects and interaction effects look like?

D. Interpreting Interaction Effects

DISCUSSION/ACTIVITY (HOMEWORK 8 - completed in class)

E. Statistics for multiple group means (ANOVA/F test)

III. Multivariate (correlational) Designs

A. Correlational designs revisited

1. Correlation vs. Causation

2. Pearson r - testing linear relationship between TWO variables

• testing r for significance

• coefficient of determination

B. Considering multiple variables

1. Partial correlations

2. Multiple regression

Multiple R/ R2

3. Factor Analysis

Send problems, comments or suggestions to: hembrees@csus.edu

California State University, Sacramento
College of Education
Department of Child Development

Updated: January, 2011