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

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

This question is partly answered by Douglas, Yeoman, and Boer (2005), who studied violence risk in a sample of criminal offenders. Douglas and colleagues looked at the predictive validity of multiple indices of violence risk. Although they conclude that "several indices were related to violent recidivism with large statistical effect sizes,...." they also found the findings to be "inconsistent with a position of strict actuarial superiority, as HCR-202 structured risk judgments-an index of structured professional or clinical judgments-were as strongly related to violence" (479).

Conclusion

With very few established exceptions, statistical prediction clearly outperforms clinical judgment. Accordingly, we certainly would not advocate use of clinical judgment over statistical prediction. For as Dawes reports,

The superiority of statistical prediction is crystal clear when clinical judgment is pitted against actuarial analysis in a situation where both are based on the same information-so that the problem is basically one of how to combine it. It also has been found that clinical judgment in psychology is inferior in situations where the important variables captured by the statistical model constitute a proper subset of the variables considered by the clinician. It is also true that the statistical models need not even be optimal. Nevertheless, clinical psychologists make a great deal of money by relying on their intuitions for combining information and for making predictions, and in courts they eschew statistical models, instead proudly proclaiming that "in my experience..." What happens here is that the "inside view" is preferred to the outside one, despite massive evidence that that outside one is superior (Dawes, 1999, pp. 37-38).

However, there are times when a combination of the two may better serve clientele. As Dawes et al. (1989) report, "Clinicians might be able to gain an advantage by recognizing rare events that are not included in the actuarial formula (due to their infrequency) and that countervail the actuarial conclusion (p. 1670).

And while such incidents might be infrequent, it is also true that the probation officers and correctional counseling specialists must have a role in decision-making that goes beyond the mere administering of the risk-assessment devices. There is a place for human judgment and experience in the decision-making process, and we must value their continued consideration.

However, as noted by Sir Frances Bacon, "We do ill to exalt the powers of the human mind, when we should seek out its proper helps" (as quoted in Hogarth (1980)). In light of the well-known tendency for justice system decision-makers to concentrate on information that is demonstrably not predictive of offender behavioral outcomes (Gottfredson and Gottfredson, 1986), and the potential consequences of this for affecting the validity of prognostication (Gottfredson and Moriarty, 2006), caution is the order of the day.

1 Portions of the preceding discussion adapted from Gottfredson and Gottfredson (1986).