Dolf Zillmann - Exemplification in Communication: the influence of Case Reports on the Perception of Issues

E xemplification is fundamental to the perception of phenomena of the so-called real world. As segments of pertinent experience that are stored in memory, exemplars provide samplings of information about past occurrences that foster dispositions and ultimately direct behavior toward similar occurrences on later encounter. A limited number of experiences thus serve as the basis for judging a larger body of similar occurrences. The implicit generalization amounts to a spontaneously executed inductive inference. Inferences of this kind are made by all species capable of adaptation through learning. Humans, no doubt, have made these inferences through the millennia, and they are still making them, routinely so and nonconsciously for the most part.

The reliance on exemplification by primary experience has, of course, not appreciably changed for nonhuman species. For humans, in contrast, it has been enormously complicated. With the refinement of communication skills, especially with the emergence of linguistic competencies, the pertinent experiences of others became communicable, and phenomena had to be judged by integrating primary experiences with communicatively conveyed ones. This broadening of the experiential base is obviously advantageous in enabling individuals to judge phenomena laying outside the bounds of their own limited and thus limiting experience. It came at a cost, however. Experiences related by others could be self-serving, inadvertently erroneous, or deliberately deceptive, forcing individuals to be on guard about others communicative intentions.

This principal condition exists for communication by media institutions as much as it pervades direct interpersonal communication, even more so because any misinformation disseminated by the media impacts vast numbers of people. Some institutions, such as the entertainment industry, claim poetic license and reject any responsibility for effects that their exemplifications might have. Supported by the intuition of numerous communication scholars, specifically their contention that people know better than to let themselves be influenced by fiction, this industry is not held accountable for misrepresentations that may foster misperceptions. However, no such license is given to media institutions that are dedicated to providing, and that purport to furnish, veridical and reliable accounts of phenomena of consequence for their audiences, potentially for the citizenry at large. Of these media institutions, the news in print, in broadcast, and in computer format, along with newslike educational efforts also irrespective of means of delivery, are of central importance.

The news media thrive on exemplification. The case report, or more accurately, the aggregation of intriguing case reports, as it appears to hold considerable public interest, may be considered the lifeblood of journalism. Accounts of societally relevant phenomena thus tend to be conveyed by samplings of cases. Such samplings are usually composed of arbitrarily extracted special cases. The focus is mostly on extraordinary rather than on typical cases. The samplings, therefore, are selective cases that do not impartially represent the population of cases that define particular phenomena. The likely result of this partial, nonrepresentative accounting is the inaccurate perception, if not the plain misperception, of the projected phenomena.

The exemplification of phenomena is, of course, often supplemented by more general descriptions. Specifications may include measured and quantified assessments. They may convey data that are collected in adherence to the principles of science. Particular manifestations of a phenomenon may be distinguished in terms of any number of criteria, for instance, and their absolute and relative incidence can then be determined. Information of this kind has been labeled base-rate information. It often accompanies exemplifications, and it is generally considered to be less partial and hence more reliable than the information provided by selective exemplars. On occasion, such information gives impetus to news reports. On other occasions, it is furnished to correct presumed erroneous perceptions from biased exemplification.

Irrespective of the reasons for including base-rate information in the projection of phenomena, however, the issue of misperception from exposure to admixtures of selective exemplification and potentially more reliable base-rate information is defined by the reception of these messages. How will recipients process the information? Will they base their perception of issues primarily on the display of exemplars? This can be expected on grounds of the built-in heuristics that ensured the survival of the species. Additionally, will recipients absorb the comparatively abstract base-rate information, process it carefully, and use it to correct false impressions invited by inappropriate exemplar aggregations? Those who believe in the careful digestion of news reports may expect that base-rate information has this power to put exemplars in their place as mere illustrations, thereby depriving them of undue influence. On the other hand, the processing of less concrete, more abstract information may be considered evolutionarily too vernal to be capable of overpowering the impressions based on the deep-rooted mechanisms of extrapolating tacit knowledge of a population of cases from a handful of actually known ones. Of particular interest are the delayed consequences of the provision of concrete versus abstract information. Are incidence rates and the like as well retained as concrete cases, not to mention extraordinary concrete cases? If not, should it not be expected that the influence of base-rate information on the perception of issues will diminish more rapidly than that of exemplification, ultimately allowing the exemplar influence to become increasingly dominant?