Title: |
Meta-analysis For Explanation: A Casebook
|
Authors: |
Thomas D. Cook, Harris Cooper, David S. Cordray, Heidi
Hartman, Larry V. Hedges, Richard J. Light, Thomas A. Louis, and Fredrick
Mosteller |
Publisher: |
Russell Sage Foundation © 1992 |
Russell Sage
Foundation
112 East 64th Street
New York, NY 1OO21
$42.50
Description:
The first two chapters in this book of 378 pages and eight chapters are
introductory and explanatory. They describe the perspective of
meta-analysis and define what explanatory meta-analysis is. Chapters
3, 4, 5, and 6 are examples of meta-analytic reviews of specific bodies of
research. These chapters demonstrate the method of meta-analysis and
illustrate the kinds of explanatory concepts the procedure produces.
The final two chapters sum up the problems, the strengths, and the
potential of meta-analysis in the social sciences.
Discussion:
This book is potentially very important for mental health professionals
and justice system professionals trying to bring the knowledge of the
social sciences into the courtroom in a responsible and effective manner.
Unfortunately, many mental health professionals and almost all justice
system professionals fail to understand the nature of scientific research.
The most common misconception is that there is research on both sides of
all issues and it is either a matter of adding up the box scores to see
which side has the most runs, or throwing the whole mess out as useless
because each side cancels out the other. This is the model that
guides almost all cross examinations of expert witnesses who rely upon
research data to support their opinions. Given this simplistic but
erroneous model it is easy to see how many judges get frustrated with the
use, or rather misuse, of science in the courtroom and throw it all out.
Science is cumulative. At the beginning of understanding and
explaining any phenomenon using the scientific method, the information may
appear weak, disorganized, and even contradictory. As research
efforts continue, however, information with higher validity and
reliability emerges. This better and more helpful information is
what can be brought into the courtroom and can serve the purpose of
increasing the accuracy of the decision-making process.
Meta-analysis is a clear set of guidelines for reviewing results of
previous studies. It uses statistical procedures to summarize the
knowledge available in a given body of research literature. This
means the process is replicated and standardized as any other scientific
procedure. It removes the element of subjectivity and the
possibility of simply differing opinions of equal merit. When a
meta-analytic review produces effects, they can be presented with more
confidence and strength as valid and meaningful.
Further, meta-analysis offers explanatory concepts to account for the
differences found in the research literature. There is an effect and
the meta-analytic review can give indication as to why the observed effect
is there. It goes beyond simple description and begins to answer the
question of why something works the way it does.
This book is clearly written. The four examples are cogent and
powerful meta-analytic reviews in their own right. The authors
provide a running commentary on their own decision-making process as they
conduct the analysis. This makes these chapters invaluable for
mental health professionals who want to learn more about meta-analysis and
how to understand it and do it. Any expert who goes into the witness
box to give an opinion which is claimed to be based on scientific research
must understand meta-analysis.
Any expert who does not understand it and continues to use the box
score approach is vulnerable not only to impeachment but also to potential
charges of unethical behavior. Any attorney who takes the trouble to
study this book, understand meta-analysis, and use scientific research
properly can confidently expect to soundly impeach any mental health
professional who does not know at least that much.
Reviewed by Ralph Underwager, Institute for Psychological
Therapies, Northfield, Minnesota.