The purpose of this research was to improve the fluency of work by introducing "see-through" or semi-transparent user interface objects such as windows, icons, tool palettes, etc. This particular project consisted of controlled laboratory experiments which evaluated divided and focused attention and visual interference issues in semi-transparent interface designs. To this end, a series of experiments were conducted which introduced progressively more realistic task elements taken from the target task domain. The results of these experiments were subsequently used to inform our design choices within selected industrial applications, in particular, 3-D modeling, animation, and painting applications. A case study of transparent user interface objects in a working application was completed. The results of these studies indicate that transparency can improve performance, but that several obstacles must be overcome before this technology can be introduced effectively into commercial products.

The purpose of this project was to identify the factors that threaten patient safety when using patient-controlled analgesia (PCA) and to obtain an evidencebased estimate of the probability of death from user programming errors associated with PCA.

A 19-yr-old woman underwent Cesarean section and delivered a healthy infant. Postoperatively, morphine sulfate (2 mg bolus, lockout interval of six minutes, four-hour limit of 30 mg) was ordered, to be delivered by PCA. A drug cassette containing 1 mg•mL–1 solution of morphine was unavailable, so the nurse used a cassette that contained a more concentrated solution (5 mg•mL–1). 7.5 hr after the PCA was started, the patient was pronounced dead. Blood samples were obtained and autopsy showed a toxic concentration of morphine. The available evidence was consistent with a concentration programming error where morphine 1 mg•mL–1 was entered instead of 5 mg•mL–1. Based on a search of such incidents
in the Food and Drug Administration MDR database and other sources and on a denominator of 22,000,000 provided by the device manufacturer, mortality from user programming errors with this device was estimated to be a low likelihood event (ranging from 1 in 33,000 to 1 in 338,800), but relatively numerous in absolute terms (ranging from 65–667 deaths).

In conclusion, anesthesiologists, nurses, human factors engineers, and device manufacturers can work together to enhance the safety of PCA pumps by redesigning user interfaces, drug cassettes, and hospital operating procedures to minimize programming errors and to enhance their detection before patients are harmed.

This project involved preparation of a report placing some of the early experimental work on DURESS and DURESS II in the context of the cognitive science literature, specifically the body of work on external representations. The report argues that cognitive scientists have primarily examined effects of the form of external representations, to the exclusion of effects due to their content. The report shows how the AH serves as a tool for modeling content for certain problem domains and illustrates the effects using results from the DURESS/II experiments.

This project studied the monitoring behaviour of nuclear power plant operators during normal operations at the Pickering Nuclear Generating Station B. Operators were observed during actual operations at the station. As well, a literature review of factors influencing monitoring behaviour was conducted. This study revealed that operators develop a number of creative adaptation strategies to overcome the deficiencies in the existing control room interface, thereby minimizing the demands associated with monitoring and improving performance.