Several decluttering methods were compared with respect to the speed and accuracy of user performance which resulted. The presence of a map background was also manipulated. Partial removal of nonessential graphic features through symbol simplification was as effective a decluttering technique as was total removal of nonessential graphic features. The presence of a map background interacted with decluttering conditions when response time was the dependent measure. Results indicate that the effectiveness of decluttering methods depends upon the degree to which each method makes essential graphic information distinctive from nonessential information. Practical implications are discussed.

The breadth/depth trade-off in menu structure refers to advantages and disadvantages of menu breadth (having fewer levels/pages of menu selections with more selections per level) and depth (having more levels/pages with fewer selections per level). Several studies (Snowberry, Parkinson & Sisson, 1983; Landauer & Nachbar, 1985) demonstrate enhanced user performance with increased breadth. However, other studies (Miller, 1981; Kiger, 1984; Tullis, 1985) fail to show an advantage in user performance with increased depth. Complicating the breadth/depth issue is the issue of the ordering of selections within each menu level. Snowberry et al. found superiority of breadth only with consistent ordering of selections within levels. Card (1982) reported that alphabetical ordering of selections is superior to functional ("logical") ordering, which in turn is superior to random ordering.

Prior work on the mechanism of carbon monoxide (CO) formation from stored wood pellets has provided the basis for a continuous process that results in the production of pellets that do not off-gas CO. It had been shown that exposure to ozone eliminated the unsaturated hydrocarbons that autoxidize to produce hydroxyl radicals, which, in turn, react with the hemicellulose to produce CO. To develop a practical process to eliminate the CO formation, a kinetic study of the continuous ozonolysis of wood fiber was conducted using a small materials auger. The reaction was found to follow a pseudo-first-order reaction such that the reduction in CO emissions was linearly proportional to the ozone exposure (concentration × time). The exposure needed to reduce or eliminate the formation of CO from the exposed fiber was around 42 000 ppm min at a flow rate of 0.57 kg/min of fiber or approximately 0.032 g of O3/kg of fiber to be passivated. The volatile organic compounds produced during the ozonolysis of fiber were analyzed with gas chromatography/mass spectrometry. Aldehydes, such as nonanal and decanal, were identified, indicating that oleic, linoleic, and linolenic acids in the fiber were ozonized. To determine the changes in the wood characteristics following exposure to ozone, thermogravimetric analysis was performed and no major changes to the wood properties were observed. To establish the industrial viability of the process, trials were conducted at scale in a commercial pellet mill. Wood pellets produced through this process showed no measurable CO off-gassing given enough ozone exposure, proving the viability of the process. The fuel properties of the resulting pellets were measured and found that the wood pellets produced from the treated fiber exhibit a similar calorific content but somewhat different moisture and ash contents from the non-treated wood pellets.

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In the summer of 1985, a survey was sent to a sample of 997 members of the Human Factors Society (HFS) living in the continental United States. A part of the survey focused on what people need to know to perform their job effectively. Respondents indicated how important each of 101 subject-matter areas was in their work. This paper discusses these results, comparing masters and doctorates, those with degrees in engineering and in psychology, and those working in various types of organizations.