In a 1955 article coauthored with Lee J. Cronbach, Meehl revolutionized the process by which psychologists provide evidence for validity of measures used in research and practice. A major contribution of this article was the acknowledgment that, for most psychological measures, validity cannot be established by a straightforward comparison with a criterion, because normally no unambiguously valid criterion measure can be found (Cronbach, and Meehl, 1955).
One would like to validate a pencil-and-paper measure of depressive tendencies by showing that it differentiates depressed from nondepressed individuals—but there is no perfectly accurate method of differentiating these two groups to serve as a criterion measure. Cronbach and Meehl explored the implications of this revelation for measurement theory and laid the groundwork for a new approach to construct validation that is central to the postpositivist philosophy of science (Cronbach, and Meehl, 1955).
Cronbach and Meehl explored the implications of this revelation for measurement theory and laid the groundwork for a new approach to construct validation that is central to the postpositivist philosophy of science, and a chief culprit in the disappointingly “slow progress of soft psychology.”
His writings reveal a keen appreciation for the virtues of clinical experience as a basis for theory and practice, and offer wise counsel on applied matters including training and certification, assessment and case conceptualization, and the role of science in informing the practice of psychology.
With a foot in each camp, Meehl was fascinated and sometimes surprised by the tensions between those psychologists who identified primarily as scientists and those who identified primarily as practitioners. Members of each faction were granted exalted social status in their respective domains—practitioners in their clinical settings, and scientists in the halls of academia—and each group could be sharply critical of the other, frequently employing unflattering emotion-driven characterizations. Meehl had little patience with such ad hominem attacks, and worked diligently to impress each camp with its limitations as an exclusive basis for claims about valid theory or optimal practice in psychology (Cronbach, and Meehl, 1955).
Limitations of Clinical Experience
As a clinician, Meehl was acutely aware of the power conferred on psychological practitioners by their social and institutional status. Psychologists are empowered to restrict individual liberty, to challenge and often change clients' construals of their life events, and even to influence law and social policy (via “expert testimony” in courtrooms and beyond). They are also, like all human beings, subject to perceptual and mnemonic biases that can cause them to draw faulty conclusions from their experiences. He stated that clinicians must and should rely on their clinical experience for guidance in many professional contexts, but they should be honest with themselves and others about the limitations of this basis for knowledge claims and for behavior.
Recommendations by the Author
In summary, Meehl believed that when no conclusive scientific data are available expert judgment is a necessary and sound basis for many clinical decisions. However, clinical wisdom, like other conclusions based on anecdotal evidence, is ...