Physics-based virtual environment for training core skills in vascular interventional radiological procedures.

Recent years have seen a significant increase in the use of Interventional Radiology (IR) as an alternative to open surgery. A large number of IR procedures commences with needle puncture of a vessel to insert guidewires and catheters: these clinical skills are acquired by all radiologists during training on patients, associated with some discomfort and occasionally, complications. While some visual skills can be acquired using models such as the ones used in surgery, these have limitations for IR which relies heavily on a sense of touch. Both patients and trainees would benefit from a virtual environment (VE) conveying touch sensation to realistically mimic procedures. The authors are developing a high fidelity VE providing a validated alternative to the traditional apprenticeship model used for teaching the core skills. The current version of the CRaIVE simulator combines home made software, haptic devices and commercial equipments.

Task analysis for the investigation of human error in safety-critical software design: a convergent methods approach.

An investigation was conducted into sources of error within a safety-critical software design task. A number of convergent methods of task- and error-analysis were systematically applied: hierarchical task analysis (HTA), error log audit, error observation, work sample and laboratory experiment. HTA, which provided the framework for the deployment of subsequent methods, revealed possible weaknesses in the areas of task automation and job organization. Application of other methods within this more circumscribed context focused on the impact of task and job design issues. The use of a convergent methods approach draws attention to the benefits and shortcomings of individual analysis methods, and illustrates the advantages of combining techniques to analyse complex problems. The features that these techniques should possess are highlighted.

Massed versus distributed wordprocessor training.

Two groups of subjects were trained on 12 basic word processing (WP) functions. One group was trained in a 'massed' 60-minute session and the other on a 'distributed' schedule of 60 min in two sessions separated by a ten-minute break. Subjects were tested on speed and accuracy immediately after training, and one week later to measure retention. It was found that the distributed training group performed significantly faster and more accurately than the massed group. This result was obtained at the end of the training period and also on the retention test. The results strongly indicate that a session of 60 min is too long for efficient WP training.

Hierarchical task analysis for ergonomics research. An application of the method to the design and evaluation of sound mixing consoles.

Hierarchical task analysis, the procedure originally devised by Annett and his colleagues for determining training needs, was applied to the task of mixing sound in order to identify the human factors requirements that need to be taken into consideration in the design and evaluation of sound mixing consoles. A number of ergonomics problems were identified and potential solutions tentatively suggested. Following the task analysis a comparative simulation study was devised in order to test the hypothesis that the functional grouping of control knobs, with increased spacing between functional groups relative to the spacing within functional groups, is superior to functional grouping per se. Reaction time data strongly support the hypothesis. This suggests that the present practice in mixing console design of arranging control panels so that the components are spaced equidistant or quasi-equidistant, irrespective of their functions, is detrimental to operator performance. The role and importance of task analysis in human factors research is discussed. Hierarchical task analysis is advocated on the grounds that the resulting task description facilitates the systematic identification of ergonomics problems.