Child Development 133 
Research Methods in Human Development

Sections 04, 68, & 69
Hembree           Spring, 2011


Quasi-experimental and Developmental Designs


I. Non-experimental designs  

A. Case study




B. One-group pre-posttest design




C. Non-equivalent control group  




D. Quasi-experimental designs  




 E. Evaluating quasi-experimental designs




II.  Developmental Designs

A. What is development?



B. The problem with studying change…



C. Developmental designs as Quasi-experimental designs



III.  Longitudinal Designs

A. Longitudinal designs allow us to

1.      observe change over time

2.      examine individual patterns (paths) 

3.      examine associations between past and present (stability) 

B. Problems with this design



C. So when is a longitudinal design appropriate?





IV.  Cross-Sectional 

A.   Age DIFFERENCES (vs. age changes)





B. Problems with this design




C. When is a cross-sectional study appropriate?


V. Cross-sequential Designs




Discussion questions:

1)   Both longitudinal studies and cross-sectional studies have problems with cohort differences.  How do cohort differences affect the conclusions you draw from your cross-sectional and longitudinal studies, respectively?  What does this have to do with external and internal validity?

2) Think of some potential cohort differences between:

·        20-, 40-, and 60-year-olds

·        3-, 6-, 9-year-olds

3)  What potential confounds are associated with longitudinal and cross-sectional designs respectively?




Send problems, comments or suggestions to:

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

Updated: January, 2011