7/20/03Copyright Ed Lipinski and Mesa Community College, All rights reserved. 1 Research Methods Summer 2009 Using Between Subjects and Within Subjects Experimental Designs

2 Agenda General Housekeeping Assignments Lesson Objective Ed’s Overview / Discussion Questions.

3 Objective “... to examine the use of between subjects and within subjects experimental designs”

4 Ed’s Overview I.Types of Experimental Designs II.Error Variance III.Between Subjects Designs IV. Within Subjects Designs V.I.V.’s and D.V.’s VI.Confounding.

5 Cohorts – APA Style… Why do you believe the APA has created writing guidelines for professional publications? What was the most helpful element associated with using APA Style? Why? What was the most difficult challenge associated with using APA Style? Why? What might I do differently next time I write an APA Style Paper? What might be some ethical considerations associated with the report I wrote or the writing style that I used?.

6 Cohorts – Top Five… Cohort ‘A’: Making Systematic Observations Cohort ‘B’: Using Survey Research Cohort ‘C’: Using Between-Subjects and Within-Subjects Designs.

7 Class Discussion What is a Between-Subjects Design? Between-Subjects: Different groups of subjects are assigned to the levels of your independent variable Pros and Cons of this Design.

8 Class Discussion What is a Within-Subjects Design? Within-Subjects: A single group of subjects is exposed to all levels of your independent variable Pros and Cons of this Design.

9 Class Discussion What is a Single-Subject Design? Single-Subject Design: The subject is exposed to all levels of the independent variable, however, you do not average statistically across subjects Pros and Cons of this Design.

10 I. Types of Experimental Designs A. Looking For Cause B. Quantitative and Qualitative Manipulation C. Between Subjects Designs D. Within Subjects Designs E. Single Subject Designs.

11 II. Error Variance A. Error Variance B. Sources of Error Variance C. Handling Error Variance Reducing Error Variance Increasing Effectiveness of I.V. Randomizing Statistical Analysis.

12 III. Between Subjects Design A. Single Factor Randomized Groups Design Randomized Two-Group Design Randomized Multigroup Design Parametric Design Nonparametric Design Multiple Control Group Design.

13 III. Between Subjects Design B. Matched Groups Design Matched Sets Distributed At Random Logic Advantages and Disadvantages Matched Pairs Design Matched Multigroup Designs.

14 IV. Within Subjects Designs A. Advantages B. Disadvantages C. Sources of Carryover Learning Fatigue Habituation Sensation Contrast Adaptation.

15 IV. Within Subjects Designs D. Dealing With Carryover Counterbalancing Complete Counterbalancing Partial Counterbalancing Latin Square Design Minimizing Carryover Treatment Order As An I.V..

16 IV. Within Subjects Designs E. When To Use Subjects Correlated With D.V. Economizing On Subjects Increasing Exposure F. Versus Matched Groups G. Types of Within-Subjects Designs Single Factor Two-Level Designs Single Factor Multilevel Designs.

17 V. I.V.’s and D.V.’s A. Factorial Designs Separate Group For Each I.V. Level Main Effects Interactions Factorial Within Subjects Designs Higher Order Factorial Designs B. Other Group-Based Designs C. Multivariate Designs – More D.V.’s.

18 VI. Confounding A.Varying With The I.V.. Maturation History.

19 Recap I.Types of Experimental Designs II.Error Variance III.Between Subjects Designs IV. Within Subjects Designs V.I.V.’s and D.V.’s VI.Confounding.

20 Between and Within Questions