Suchergebnisse

This is an account of my 8-year tour as Human Factors editor during the last decade of the past century. I accepted this appointment with the understanding that the journal, although highly successful, was entering a period of transition during which problems were surfacing that would require some strategic redirection. Together with Human Factors and Ergonomics Society staff and my editorial board, which in addition to peer review I relied on heavily for advice on journal policy, we effected a number of changes. In this article, I review those changes along with the issues they were designed to address and the reasoning behind each. It remains for the reader to judge whether the net effect of these changes has been for the better.

Quantitative models of "thermal comfort" commonly involve prediction equations with "votes" on a thermal sensation scale as the criterion and physical variables (temperature, humidity, activity, clothing) as predictors. One established model of this sort was developed by Fanger using laboratory data. The present study sought to validate this model in realistic indoor settings by correlating predicted with measured thermal sensation judgments for 521 resident employees and students. Several demographic and cognitive variables were also measured, and direct comfort judgments were taken for comparison with the main criterion. Results provided weak support for the validity of the physical-predictor model. More important, however, was the substantial increase in predictiveness contributed by cognitive variables, and the demonstration that "comfort" defined by thermal sensation votes is not the same as that measured directly. Implications for energy conservation proposals are discussed.

Two experiments sought to determine whether and if so, how, performance varies as a function of the manner in which a progressively unfolding decision problem is displayed over time. A hurricane-tracking scenario was adapted to the "optional-stopping" paradigm, such that subjects elected to continue sampling information or to make a terminal decision (evacuate or stay) at successive points in the storm's development based upon cumulative evidence and future expectations. The display manipulation was minimal in that it applied only to nonpredictive historical data (position information). Despite this conservative test, display formation had a significant effect when time pressure was involved: subjects reached earlier and better terminal decision under the graphic than the numerical format (Experiment 2). The differences reduced to nonsignificance under self-pacing (Experiment 1), although significant improvements were obtained by use of a simple aiding device (calculation of worst-case probabilities). Results are generally consistent with Hammond's cognitive consistency theory.

An experiment was conducted to determine how the quality of a human judgment (in this case, military threat diagnosis) is affected by various levels of preprocessing applied to the raw predictive events when such processing is carried out by the human and by a machine aid. Subjects were required to estimate the threat of attack on the friendly position (criterion) based on observed activity levels (cues) and designated threat potential weights of various enemy positions. Overall threat judgments were made under conditions in which a prior overt estimate of position activity levels was or was not required. Machine-aiding conditions were as follows: (1) no aiding, where subjects simply observed raw events in real time, (2) automatic tabulation of events, and (3) automatic computation of events. Finally, the rate of event occurrences was manipulated. When subjects made overall criterion judgments (threat evaluation) intuitively on the basis of events observed in real time, their performance improved markedly by interposing cue estimation, even if cue estimation was fairly inaccurate. If events were computed automatically, permitting a more analytic threat judgment, performance improved and the redundant estimation step was not helpful. If events were merely tabulated, estimation was helpful, but to an extent midway between the raw-observation and automatic computation conditions.

Two points of view concerning desirable goals of effective educational programs for engineering psychologists are discussed. One view emphasizes the production of first-rate experimental psychologists who hope to see their efforts contribute to the improvement of man-machine systems. The other view expresses the need for true hybrid scientist-engineers or system scientists who possess a command of the facts and methods of the behavioral and biological sciences as well as the physical sciences. The rationale and implications of these views relative to educational programs for engineering psychology are explored.