Outlined and solid-sur/aced metric histoforms and polygons we;e employed in an identification task where choice forms were fixed at 0 deg and target forms at six points along the temporal horizontal meridian in the periphery (nasal retina). Accuracy in the identification of solid-surfacedpolygons in the far periphery (80 deg from the fovea) was much higher than has been previously reported. Polygons were identified more quickly than h istaforms, but a significant difference was not obtained between the speed of identification of outlined and solid shapes. Combined speed and error data indicated that shape [histoform or polygon) is the most salient dimension ofa form less than 50 deg from the fovea. whereas beyond 50 deg from the fovea the surface (outlined or solid) of a form is its most salien t dimension. Finally. comparisons of the functional relations provided by these performance data with anatomical and physiological data produced the following hypothesis: Spatial summation ofrod receptors beyond 20 deg of angular eccentricity in the nasal retina is directly proportional to the density of rod receptors.

Eight albino rats were trained to bar-press

Discrimination performance of two classes of patterns (histoforms and polygons) was determined as a function of the size of the forms at three levels of complexity (4, 6, and 8 columns or angles). The visual angle subtense of the stimulus forms was varied over a range of sizes from near threshold (1.88 min.) to well above it (16.56 min.). The important finding is that below a visual angle of 8 min. discrimination of the form is essentially identical in terms of both accuracy and speed of identification. At angular sizes above 8 min. consistent differences in the rate of processing the two classes of forms emerged. The results were interpreted as indicating that identification performance depends on “emergent features” of the forms as they increase in size.

A comprehensive health and safety training program was developed for entry level underground and surface coal miners in West Virginia using the Instructional System Development approach. To develop this program a safety task analysis was first conducted of all entry miner tasks. In conjunction with the task analyses, an investigation of the educational level, learning ability, demographic characteristics and attitudes of the miners was made. Training objectives and test items were developed from the task analysis data. Instructional materials were developed based on the derived learning objectives and behavioral characteristics of the trainees. The programs were implemented into the State during 1977. Following the Implementation an extensive evaluation program was conducted. The program development process and the evaluation data are briefly described in this paper.

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