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Warnings are one of several hazard control methods used to protect employees and property against danger and loss. This article surveys a set of factors known to in uence the effectiveness of workplace warnings. The description of empirical research is organized around a communication-human information processing (C-HIP) model. The model begins with a source entity attempting to relay a warning message through one or more media/sensory channels to one or more receivers. At the receiver, processing begins when attention is switched to the warning message and then maintained while information is extracted. Processing continues through the successive stages of comprehension, beliefs and attitudes, motivation, and ends with compliance behaviour. Any of these stages can be a bottleneck that causes processing to stop, diminishing the effectiveness of the warning. The factors that are in uential at each stage are described. The C-HIP model provides a structure to systematically examine factors that can cause risk communication to fail and for nding ways to improve risk communication in the workplace. KE Y W O R D S:warnings; safety; hazard control; risk perception; human information processing

Designing numeric keypads for point-of-sale devices to optimize keying speed and accuracy while efficiently utilizing touch screen real estate is a challenge. Existing design guidelines for touch screens are applicable to only specific classes of devices and fail to consider user variables such as finger size. The present study investigated keying speed and error rates for various keypad configurations in a simulated retail keying task. Finger sizes were taken into account. Results support the use of compressed (2 mm or less) interkey spacing in keypad designs. No significant effects of key size were found. Gender differences in keying speed and accuracy were explained by finger size differences between males and females. Implications for the design of touch screen user interfaces in point-of-sale applications are discussed.

This paper describes several ways in which new technologies can assist in the design and delivery of warnings. There are four discussion points: (1) current product information can be delivered via the Internet; (2) computer software and hardware are available to assist in the design, construction, and production of visual and auditory warnings;(3) various detection devices can be used to recognize instances in which warnings might be delivered; and (4) a warning presentation can be modi®ed to ®t conditions and persons. Implications, example applications and future prospects of these points are described.

Very little has been published on methods for creating and testing text messages for product warnings. This paper describes how the three main principles of usability engineering (prototyping, empirical user testing, and iterative design) can be applied to the design and evaluation of warning text. Pre-prototype activities that help define the warning requirements are described, followed by a discussion of guidelines for creating and testing design prototypes. Finally, a methodology for formally testing the effectiveness of warning text is presented. The procedure described should be useful to human factors practitioners who are responsible for creating or evaluating textual warnings.