Child Development 133 
Research Methods in Human Development

Sections 04, 68, & 69
Hembree           Spring, 2011

 

Advanced Designs

I. Introduction - Design Issues

Design = Plan of Experiment ("blueprint")

Ask questions:

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

 

 

D. Repeated measures designs

 

 

  • Advantages and disadvantages

 

 

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 

A. Advantages of factorial designs

 

 

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?

 

 

C. Interaction effects 

an example:...

 

Time of Day

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