Human Factors: The Journal of the Human Factors and Ergonomics Society

The contributions which human factors studies can make to industry are discussed in this paper. Broadly, contributions can be made in two areas, product design and the design and use of manufacturing equipment. The latter area is the major concern of this paper and some of the work done on ordinary manufacturing equipment is described. A major problem is the validation of human factors recommendations and it is pointed out here that the normal short-term evaluation is inadequate. For the effective use of people in industry it is necessary for human factors personnel to take a wider view of their contributions than has been common in the past and to consider their role in relation to the long-term operation of the whole plant.

Ergonomic measurements of noise, lighting and room climate were made in 15 large-space offices in Switzerland. At the same time, 519 employees were given a questionnaire about working in such offices (continuation of work, distractions, disturbances, interpersonal relations, communications, etc.). The correlations among measures indicated the factors that have special influence on the judgments of the large-space office. The results form an objective, usable decision base for the selection and planning of an office building.

The skills shown by an experienced worker are necessary for the new candidate to acquire but are not sufficient for his becoming proficient. Other skills acquired during the learning process are necessary to successful execution of the job even though they are no longer needed when the experienced worker standard has been reached. This suggests that it is necessary to assess a candidate not only in terms of the skills found in the behavior of experienced workers but also in terms of the main skills required during the learning process. This approach would allow for greater predictive power of the selection assessment.

Ergonomists working in the military area need to modify some of their assumptions about operator (or worker) behavior when they transfer to work in the industrial area. The goal of the ergonomist in the latter area should not be job simplification as it often is in the former area. Job simplification is a frequent outcome of human factors approaches which consider only what a man can do. In the industrial setting, cost-effective attainment of long-range industrial system efficiency and effectiveness cannot be achieved unless consideration is also given to what a man will do. This paper describes some of the factors important to the ergonomist in industrial work and suggests that their consideration is especially important if the ergonomist is to consider himself as a systems designer rather than a “knobs and dials” man.

The Human Engineering Group was asked to investigate a microwelding operation considered by management to be a critical problem area. The operation, involving manual welding and trimming of wire grids, was excessively demanding on human resources. In spite of hourly break periods, the operators complained of excessive fatigue, back strain, and leg pains. The Human Engineering Group, in conjunction with the Industrial Design Group, studied the problem and recommended a drastically revised work environment. The rationale for developing design solutions is discussed, followed by the translation of design concepts into hardware definitions. A description follows of the monitoring of the construction and operations performed on a prototype.

The visibility of difficult visual tasks can be improved by modifying the task, increasing the light level, or changing the character of the light. In practical applications the most effective approach is to determine the optimal character of light for each visual task. Seventeen different types of light are described and some typical applications are discussed.

The paucity of human factors work in computer system design is noted, and reasons for this are elaborated with particular reference to computer-based management information systems. The main obstacle to such human factors endeavor would appear to be the lack of appropriate investigatory techniques. To remedy this deficiency a method is proposed which derived from the field of psychotherapy. Pilot studies are reported which demonstrate the technique and indicate how the data obtained may be interpreted. An appraisal of the potential of this technique in the management information system field is presented.

Forty-eight subjects were required to detect long-duration brightness changes (signals) and ignore short-duration changes (nonsignals) occurring on an electroluminescent panel during a 60-min. monitoring session. Signal-to-nonsignal ratios (constant 1/9, changing 1/9 to 1/1, or constant 1/1) and signal detectability (0.3 or 0.6 sec. difference between signal and nonsignal duration) were combined factorially in a between-subject design. The changing signal-to-nonsignal ratio resulted in an intermediate level of signals correctly detected. The classical decrease in percent of signals detected over time occurred in the constant 1/9 ratio condition under both levels of signal detectability. Signal detection theory analyses were restricted to low detectable signals. A marked increase in β over the monitoring session occurred in the constant 1/9 ratio condition, whereas β remained low and relatively constant in the other signal-to-nonsignal ratio conditions. Both the limitations of a decision-theory interpretation and the implications of using changing signal-to-nonsignal ratios for manipulating the observer's effective response criterion were discussed.