The Effects of Using a Hypertext Tool for Selecting Design Guidelines

Designing a User-System Interface (USI) is a complex task that has been approached in many ways. One approach has been to use USI design guidelines to help improve the quality and consistency of USIs. To be effective, a general set of guidelines must be tailored to a specific application. This study investigated the effects of using a hypertext design aid (DRUID, Dynamic Rules for User Interface Design) for the selection of USI guidelines by both experienced and novice guideline users. Results indicate that, in general, the participants performed their tasks as well with DRUID as with the book. However, the participants accessed the material differently for each medium and they selected more guidelines that were relevant when using the paper book. Subjectively, the software was preferred because it provided assistance in the selection process and provided additional time-saving design aids not available in the book.

Autonet: An Application of a Neural Network Simulation as a Tool for Planning Office Layout

When people have trouble finding their way through office settings, there are costs in terms of poor communication, lost efficiency, time, and stress (Brill, et. al., 1984; O'Neill, 1991; Weisman, 1981; Zimring, 1981). To cope with wayfinding problems, facilities managers often have to resort to partial solutions, like complex signage, color coding schemes, and other methods to guide people. AutoNet is an experimental computer-aided design and planning tool that predicts the paths people will take through a building based on the layout of the space and their level of experience. AutoNet represents environmental information by using an artificial ‘neural network’ simulation. The mechanisms of this simulation are based on the physiology of the brain. Knowledge about the layout of the environment is represented through a network of interconnected processing elements, modeled on the behavior of groups of neurons in the brain. Thus it can create its own rules for predicting worker behavior rather than using predetermined sets of rules that a typical expert system would rely on. This system has great flexibility since there are no rules to rewrite for each setting it evaluates. The predictive validity of this simulation was empirically validated (O'Neill, 1991). This software runs within a popular and commonly available CAD software package in an MS-DOS environment. AutoNet is viewed as a “macro-ergonomic” tool to enhance the office work environment (Hedge & Ellis, 1990).

Isometric Strength Capability for a Vertical Wheel Turning Task

This paper reports on the measured isometric strength capability of 125 male and 125 female college students performing a one-handed wheel turning task. Three measures of isometric strength were used: (1) a three-second average of steady state levels taken from a six-second exertion, (2) the largest value (peak) from the same six-second exertion, and (3) a maximum exertion level taken from a separate “ramp-to-peak” exertion. Standardized whole-body strength measurements for the legs, arms, and torso as well as grip strength were also taken for each subject. The results presented in this paper demonstrate average isometric wheel turning strengths (torques) ranging from 109 to 152 N-m for males and 66 to 91 N-m for females, depending upon the strength measure used. The three strength measures were highly correlated, but produced significantly different estimates of strength. The three-second average produced the lowest estimate while the ramp-peak value produced the highest. Wheel turning strengths were also highly correlated with the standardized whole-body strength measures and with grip strength. Multiple regression models developed to predict wheel turning strength using these values accounted for 69 to 71 percent of the variation in the measures. The model results also suggest that grip strength plays an important role in determining wheel turning strength capability.

Design of Instrument Approach Procedure Charts: Comprehending Missed Approach Instructions Coded in Text or Icons

The objectives of this experiment were to determine whether coding missed approach instructions in text or icons would result in more efficient information transfer, and if the information transfer efficiency for either coding technique was dependent upon the level of information content. Twelve pilots currently licensed for instrument (IFR) flight participated as subjects. Text instructions were either taken directly or developed from instructions found on National Ocean Service (NOS) instrument approach procedure charts. These instructions possessed one of three levels of information content: low, medium, and high. Across the range of information content levels, iconic missed approach instructions were comprehended more quickly and as accurately as instructions coded in text of the font style and size used by NOS. Regardless of coding technique, report accuracy was significantly worse for instructions with a high information content level. Pilots indicated that in single pilot IFR conditions, they would rather have the iconic than the text version of the missed approach instructions.

Work Practices and Fatigue in the Long Distance Road Transport Industry in Australia

A Questionnaire was used to obtain information from 960 long distance truck drivers about the drivers” experience, type of employment and their working conditions, type of driving operation, as well as details of their last trip and their last working week. Operations specifically designed to combat driver fatigue by provision of a relief driver in a team operation did not appear to achieve their intended outcome. The potential benefits of such operations appeared to be outweighed by the greater distances and lack of flexibility that characterised these trips.

Toward an Agenda for Error Research

There has been a great increase in interest in human error and its impact on the individual and society in recent years. The present symposium is but one example of this in a restricted area. Several general accounts of human error and the psychological mechanisms which underlie it have appeared in recent years, but for the most part these have concentrated on accounts of error based on research on the cognitive psychology of the individual. In this paper I discuss a more general framework for the stidy of error, not for the purpose of understanding it alone, but rather for putting into place a program for muitigating its effect in the larger arena of social impact. Only by integrating research at a variety of levels and using a variety of techniques can we hope to understand and control the effects of error.

Analogue and Digital Displays for the Detect, Diagnose and Correct Phases in Fault Management

Performance effects of using different display information formats for the detect, diagnose and correct task components of fault management were evaluated in this preliminary study. Data for accuracy and response times were collected for a detect task, a detect and diagnose task, and a detect, diagnose and correct task across three levels of display information format. Levels of display information format included a digital format, an analogue format, and a combined (digital and analogue) format. Predictions for the appropriate level of display information format for the fault mangement tasks were based on the multiple information format concept. In general, the results obtained in this study failed to support the predictions of the multiple information format concept.

Review of Concepts and Approaches to Complexity

The objective of this paper is to review research dealing with the role of complexity in functions and tasks commonly allocated to the operators/users. This topic is complex and not well-structured. We have reviewed principal approaches to provide better structure for the psychological domain of complexity. The research reviewed is partitioned into three categories: procedural, cognitive, and conceptual complexity. What we were after in the review was to find quantifiable attributes of complexity in cognitive tasks and skills and how to use these attributes to manage complexity during system design.

Perceived Exertion in Isometric Muscular Contractions Related to Age, Muscle, Force Level and Duration

This research was concerned with studying the development and growth of perceived effort of long-term isometric contractions as a function of muscle group (biceps vs quadriceps), of subjects with different age groups (20–29 vs. 50–59 years old) on long-term muscular isometric contractions (5 minutes) at different levels of %MVC (20, 40, 60, 80 and 100 %MVC). An experiment testing 20 subjects each performing 10 conditions (two muscle groups × five levels of %MVC) showed that the older age group reported Significantly higher perceived exertion at higher levels of %MVC and across time. Furthermore, subjects experienced a higher and faster increase in their perceived exertion when the level of %MVC and time increased.