Experimental Research: Design, Problems, and Applications, Slides of Research Methodology

Download Experimental Research: Design, Problems, and Applications and more Slides Research Methodology in PDF only on Docsity! Experimental Research docsity.com Introduction • Experiments are part of the traditional science model • Involve taking “action” and observing consequences of this action • Can collect data using rigorous control • A good example is Albert Bandura’s Bobo doll study: “Transmission of Aggression Through Imitation of Aggressive Models” (1961) – Click on the following link to read this classic paper: – http://psychclassics.yorku.ca/Bandura/bobo.htm docsity.com The Double-Blind Experiment • Neither researchers or subjects know who is experimental group • “blinding the study” • To reduce experimental bias docsity.com Selecting Subjects • Generalizability important • Probability sampling where possible • Random assignment essential to ensure no difference between experimental and control groups • Sometimes “matching” used – Individuals are matched on important characteristics • Problem of “volunteer” subjects docsity.com The Classical Design and Variations • “Pre-experimental” Designs (no random assignment – A. One shot case study – B. One group pre-test-post-test design – C. Static group comparison • “True Experimental” Designs (random assignment) – D. Pretest-Post-test control group design – E. Post-test only control group design – F. Solomon Four-Group design docsity.com “True Experimental” Designs (cont.) • F. Solomon Four-Group design (Bandura’s Design): Exp. Obs1 Tx Obs2 Ctrl. Obs1 Obs2 Exp. Tx Obs2 Ctrl. Obs2 docsity.com Problems of Internal Validity • Is change in DV actually caused by IV? • A. Problems concerning Subjects – 1. Selection bias – 2. Experimental Mortality – 3. Rivalry – 4. Demoralization docsity.com Problems (cont.) • B. Problems with experimental procedure – 1. Testing – 2. Instrumentation – 3. Causal time order – 4. Diffusion – 5. Compensation to control group • C. Problems with time – History – Maturation docsity.com The Hawthorne Experiments • Four experiments: – A. Used Three experimental groups and no control group. Found productivity increased when lighting improved. – B. Experimental and control group used. Experimental group had increased lighting. Both groups showed increased productivity. – C. Experimental and control group used. Experimental group had decreased lighting. Both groups showed increased productivity. – D. Two women studied under varying lighting conditions. Subjects increased productivity according to which lighting conditions (more or less) researchers said were “good” docsity.com Strengths and Weaknesses of Experimental Design • Strengths – Establishing causality – Control – Longitudinal research – Replication • Weaknesses – Artificiality – Experimenter effect – Sample size docsity.com The Field Experiment • Used in sociology • Natural setting • Uses statistical control • For an excellent example of a field experiment, click link below to read a summary of “The Impact of Television: A Longitudinal Canadian Study” by Tannis Macbeth Williams – http://world.std.com/~jlr/comment/tv_impact.ht m docsity.com