Clinical Versus Actuarial Judgments in Criminal Justice Decisions: Should One Replace the Other?

Federal Probation, Sep 2006 by Gottfredson, Stephen D, Moriarty, Laura J

Why, then, should we continue to allow (indeed, require) probation officers and case managers to exercise individual discretion, when an actuarially-derived tool may be expected to perform better? As Westen and Weinberger (2005) remind us in a discussion of the pioneering work of Paul E. Meehl on clinical and statistical prediction, even though statistical prediction will routinely outperform clinical prediction, we should not lose sight of the fact that "actuarial procedures are far from infallible, sometimes achieving only modest results" (Dawes et al., 1989, p. 1673). [For a discussion of the methodological and statistical problems associated with such applications and the resultant fallibilities of such procedures, see Gottfredson and Moriarty, 2006]. Still, as Dawes (2005) concludes, "whenever statistical prediction rules (SPR's) are available for making a relevant prediction, they should be used in preference to intuition" (p. 1245).

But does the superiority of actuarial procedures over clinical judgment mean that there is no place for clinical judgment in predicting behavior? The answer is no: "an enormous amount of prediction is made by human judgment" (Darlington, 1986, p. 362). Simply put, clinical methods of decision-making rest in the decision-maker's head, while statistical or actuarial methods eliminate the human judgment with the "conclusions rest(ing) solely on empirically established relations between the data and the condition or event of interest" (Dawes et al., 1989, p. 1668). There are instances when clinicians can make valid inferences (Westen and Weinberger, 2005), and there are times when it is preferable to use both clinical and statistical judgments to predict behavior. As Darlington (1986, 362) reports, "This research does not suggest human judgment is generally unnecessary; rather it indicates that the most accurate predictions generally result from a predictive system in which human judgment and statistical analysis are mixed according to prescribed rules." Moreover, Dawes et al. (1989) assert that there are instances when clinical judgment might improve the actuarial method. They cite specifically the following examples: "judgments mediated by theories and hence difficult or impossible to duplicate by statistical frequency alone; select reversal of actuarial conclusions based on the consideration of rare events or utility functions that are not incorporated into statistical methods; and complex configurai relations between predictive variables and outcome" (p. 1670).

The Place for Personal Judgment

As some assert, the dilemma once posed by "using either the head or the formula is no longer the main focus of contemporary decision research. Rather, the focus has long ago shifted to evaluating the use of both modes of information combination in tandem" (Kleinmuntz et al., 1990, p. 146; and see generally, Litwack, 2001).

In some of the most recent research examining violence risk assessment (Hanson, 2005), we find that the question has shifted from whether violence can be predicted, to what is the best method of risk assessment. The validation research typically found that a series of measures reviewed in the article showed moderate accuracy in predicting violent recidivism. The question then is: Might the prediction have been improved if clinical judgments were included as well?