7/20/03 Copyright Ed Lipinski and Mesa Community College, 2003-2009. All rights reserved.

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Research MethodsSummer 2009

Using Between Subjects and Within Subjects Experimental Designs

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Agenda

• General Housekeeping

• Assignments

• Lesson Objective

• Ed’s Overview / Discussion

• Questions.

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Objective

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

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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.

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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?.

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Cohorts – Top Five…

• Cohort ‘A’: Making Systematic Observations

• Cohort ‘B’: Using Survey Research

• Cohort ‘C’: Using Between-Subjects and Within-Subjects Designs.

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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.

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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.

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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.

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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.

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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.

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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.

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III. Between Subjects Design

• B. Matched Groups Design• Matched Sets Distributed At Random• Logic• Advantages and Disadvantages• Matched Pairs Design• Matched Multigroup Designs.

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IV. Within Subjects Designs

• A. Advantages• B. Disadvantages• C. Sources of Carryover

• Learning• Fatigue• Habituation• Sensation• Contrast• Adaptation.

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IV. Within Subjects Designs

• D. Dealing With Carryover• Counterbalancing

• Complete Counterbalancing• Partial Counterbalancing• Latin Square Design

• Minimizing Carryover• Treatment Order As An I.V..

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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.

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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.

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VI. Confounding

• A. Varying With The I.V..• Maturation• History.

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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.

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Between and Within

Questions