Chapter 12.  Accuracy: Components and Processes

Abstract

     Social perception in general, and accuracy in particular, can be viewed as being composed of different components.  Several different componential approaches to accuracy (Cronbach’s (1955), Kenny’s (1994), and Judd & Park’s(1993) are described, reviewed, and critically evaluated.  For example, if Roberto accurately predicts the weather to be warm and sunny tomorrow, is that because he is an inveterate optimist who usually predicts good things, because he usually predicts the weather in particular to be nice, or because he has based his prediction for tomorrow on the latest and most valid in meteorological tools?  Each of these reasons can be viewed as a “component” (one component is his tendency to predict good things, another is his tendency to predict uniquely good weather, the third is his knowledge of tomorrow’s weather in particular).  This chapter concludes that although componential approaches provide important and useful information about the processes of social judgment and sources of accuracy and inaccuracy, the claim that one “must” assess components in order to assess accuracy — often made by advocates of componential approaches – is not justified.  Several productive and instructive theoretical perspectives on accuracy that are not explicitly componential are reviewed.  Although they do not “conflict” with componential approaches, they do demonstrate that one can productively study accuracy without performing an explicitly componential analysis.  These include correlational approaches to accuracy (which includes an instructive subsection emphasizing the similarities of assessing social perceptual accuracy to those of assessing construct validity in the social sciences); Brunswik’s Lens Model; Funder’s Realistic Accuracy Model; and Dawes’ Improper Linear Models.  Nonetheless, this chapter also concludes that understanding componential approaches also contributes to a greater understanding of results even obtained from approaches that do not specifically perform componential analyses.

EXCERPTS:
A stopped clock is right twice each day.  That does not make it a good clock.What does this have to do with social perception?  More than it seems.  Let’s return to my successful prediction (from Chapter 11) that Mike Piazza would hit a home run when he came up to bat with the bases loaded.  That makes me look like a pretty darn good baseball prognosticator, doesn’t it? Not necessarily.  Maybe I always predicted that Mike will hit a home run.  Maybe I always predict everyone will hit a home run.  And it could even be worse than that: Maybe I always predict all baseball players will do great things, whether in the field, at bat, or on the base paths.  (This would be logically absurd, because it would mean that I would predict both that Mike would hit a grand slam and that the pitcher would strike him out.  A detailed discussion of people’s ability to hold mutually exclusive beliefs [see, e.g., Dawes, 2001], however, is beyond the scope of this book.)
Even though I might have happened to have been right that one time, I could not necessarily be considered a particularly astute judge of baseball.  One could think of my prediction regarding Mike’s at bat as stemming from several sources or components: 1) My overall tendency to think well of baseball players; 2) my overall tendency to predict that batters will hit home runs (over and above my general tendency to think well of players); 3) my overall tendency to think that Mike is a good hitter (over and above my general tendency to think well of players); and 4) my specific tendency to predict that Mike will hit a home run (over and above my tendency to think well of players, to predict that they, in general, will hit home runs, and to think well of Mike as a hitter in general — ok, I admit it, even I am getting dizzy at this point).  Each component of my prediction can be accurate to some degree, and each contributes both to my prediction for Mike, and my overall likelihood of being accurate (across lots of judgments or predictions).

Components of Accuracy
This type of thinking inspired Cronbach’s (1955) (in?)famous review, and at least two other more recent perspectives (Judd & Park, 1993; Kenny, 1994), all of which identified several processes contributing to social perception and which argued that accuracy needs to be separated into different components reflecting these different processes.  This section describes each of these three componential approaches to the study of accuracy.
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  Non-Componential Models: Final Comments
Correlational approaches to accuracy, including but not restricted to the Lens Model and RAM, do not oppose or contradict componential approaches.  Indeed, it is quite possible to perform a Lens Model or RAM analysis via components, if one felt that would be useful or important (Kenny et al, 2006).  Furthermore, simple correlations between criterion and judgment go a long way toward eliminating many of the often irrelevant artifacts and biases identified by Cronbach (1955) and Kenny (1994).  Nonetheless, my point for presenting them here has not been to argue that they refute componential approaches.  My point, instead, has only been to demonstrate that some very sophisticated and successful noncomponential models and approaches to accuracy have been developed.  One will find no mention of components in Brunswik (1952) or Funder (1995), or in many other influential articles and books on accuracy (e.g., Ickes, 1997; Jussim, 1991; McCauley et al, 1980; Swim, 1994).  Components are interesting and important, but claims that one must always assess components when studying accuracy are not justified.