Proceedings of the Human Factors and Ergonomics Society Annual Meeting

Human performance and human error in medicine have emerged as critical health care issues affecting the entire practice of medical treatment and health care delivery. Human factors professionals, particularly members of the HFES, can make major contributions to health care systems, but there is a lack of transition between problem domains. Since the human factors profession has been built on the study and improvement of high-risk systems, the current state of medical practice is clearly an opportune environment in which to operate. This panel will address several practical “ironies” of the current challenges to build improved bridges between key aspects of HFES expertise and the needs of the medical community.

Human factors and ergonomics are quickly evolving and new areas of application are introduced around the world. In industrially developing countries (IDC's) the emphasis was in the past on physical workload. With the introduction of computers there has been a sudden shift in interest, and the problems of HCI and usability of complex systems have become paramount. This panel will discuss the changes in ergonomics, and how they are affected by changing work ethics, and changing needs of the society. It is argued that ergonomics is well suited to adapt to new goals and respond to difficult challenges. As a result we need to prepare ourselves in education and training to meet the new demands in ergonomics. Can certification programs for ergonomists be flexible enough to consider current needs, and can teaching programs incorporate new knowledge? What are some effects on the type of research that will be conducted in the future. How will ergonomics professionals deal with design and applications. These are some of the issues that will be discussed in this panel session.

The present research examines: (a) the accuracy of three face description methods, and (b) the effects of post-exposure description and imaging activities on subsequent face recognition performance. Participants viewed a sequence of six target photographs, and after each, performed one of three description tasks: generated their own set of descriptors, checked-off descriptors from a pre-existing list, or rated the same set of descriptors on bipolar scales. Other participants performed a distractor (control) activity. Additionally, participants were either told or not told to image the targets while they simultaneously performed the description tasks. Results showed that the checklist task lowered subsequent recognition performance compared to the generate task. Imaging with the generate task facilitated recognition, but imaging with the checklist and rating tasks degraded recognition. The generate task produced the highest quality descriptions as determined by other participants' performance in matching the descriptions to face photographs. The checklist decrement is discussed in terms of memorial confusion initiated by the presence of irrelevant face cues. These results indicate that descriptor generation is the preferred method of collecting eyewitness' face descriptions.

As a sequel to a study which analyzed the annual meetings of the Human Factors Society (HFS) during the period 1959–1972 (Meister, 1995), the following is a study of the characteristics of Human Factors/Ergonomics (HF/E) research as these have changed over the years 1965–1994.

Four factors were manipulated to assess the possible performance decrements caused by concurrent performance of a visual and an auditory task. For the visual task, memory load and the degree of attentional switching were manipulated. The nature of the memoric information and the intelligibility of the speech signal in the auditory task were also manipulated. The level of single-task performance was compared with the performance of the same task under dual-task conditions to determine which factor lead to the greatest dual-task decrement. The results demonstrate that memory load and the nature of the memory representation had little effect on the performance of a concurrent task. Visual attention switching had a large effect on the amount of dual-task decrement.

The perceived size of a stimulus can be greatly influenced by the surrounding depth cues. The effect size of the Ponzo Illusion was tested in a virtual environment with many depth cues (MC) and few depth cues (FC) conditions. The effect of size and the depth cues on the perceived proximal size of the stimulus was measured. Methods. A modified Wheatstone stereoscope was used to present the stimuli on a monitor positioned 80 cm from the subjects. The subjects used a 6AFC confidence rating scale to indicate whether the first or second of two sequentially presented stimuli had a greater proximal extent. The ‘many cues’ (MC) condition included texture, relative height, foreshortening, linear perspective, relative brightness, and relative size. The few cues condition consisted of linear perspective, relative height, and relative size. Stimulus size (proximal extent) was varied independently from all other depth cues. Results. Both depth cue context and proximal size were found to have a significant effect on the perceived proximal size for FC conditions. However, for MC conditions only the depth cues, and not proximal size, had an effect on perceived proximal size. The effect size for both depth cues and proximal size had a significant linear trend. But proximal size had a larger trend that was significantly related to the size constancy function.