1. SINGLE - CASE, QUASI-EXPERIMENT, AND DEVELOPMENTAL RESEARCH

2. Single Case Experimental Designs (formerly called single-subject designs) Measured from baseline period to treatment periods Reversal or withdrawal design Called an ABA design Baseline (A)  Treatment (B)  Baseline (A) The use of praise as a treatment to measure the improvement of a child’s school performance Measure test scores  give regimen of praise for correct homework problems  measure test scores

4. Multiple Baseline Designs Change is observed under multiple circumstances The manipulation is introduced at different times Determines that the manipulation caused change

6.  Used when control features of experimental designs cannot be achieved  For example, the independent variable cannot be manipulated  Internal validity may be affected

7. One-Group Posttest-Only Design

8. Nonequivalent Control Group Design

9. One-Group Pretest-Posttest Design

10. Nonequivalent Control Group Pretest-Posttest Design

11. Cross-Sectional Method – persons of different ages measured at the same point in time Longitudinal Method – same group is observed at different times (as they age) Sequential Method – combination of 1 and 2

12. Cross Sectional Method Year of Birth (cohort)Time 1: 2005 Group 1195055 years old Group 2194560 years old Group 3194065 years old

13. Longitudinal Method Year of Birth (cohort) Time 1: 2005 Time 2: 2010 Time 3: 2015 Group 1:1950 55 yr  60 yr  65 yr

14. Sequential Method Year of Birth (cohort) Time 1: 2005 Time 2: 2010 Time 3: 2015 Group 1:1950 55 yr  60 yr  65 yr Group 2:1940 65 yr  70 yr  75 yr

15. Comparison of Longitudinal and Cross- Sectional Methods Strengths: - Can attribute changes to development - Can examine variables at a later time - As a hybrid, the sequential method shares virtues of both methods Weaknesses: - Expensive - Difficult - Mortality