Accession Number : ADA235703

Title :   The Effects of Display Failures, Polarity, and Clutter on Visual Search for Symbols on Cartographic Images.

Descriptive Note : Final rept.,

Corporate Author : HUMAN ENGINEERING LAB ABERDEEN PROVING GROUND MD

Personal Author(s) : Dye, Craig J. ; Synder, Harry L.

Report Date : APR 1991

Pagination or Media Count : 49

Abstract : Little research has been conducted about human performance in symbol search of cartographic images on matrix-addressable displays. Alphanumeric studies have researched failures and polarity on such displays but not using cartographic images. Two studies were conducted which required subjects to search for symbols on cartographic images under various conditions of failure, polarity, and background clutter. Response time and accuracy were measured. Generally, high clutter impeded performance more than low clutter, and negative contrast produced slightly better performance than positive contrast. Horizontal line failures affected search ability more than vertical line or cell failures did, particularly when the failures were in the on mode rather than the off mode. Further, it was discovered that while previous alphanumeric studies found effects at 3% failures or greater, effects were observed for the present studies at 2% or greater, apparently because of the presence of map information on the display. Recommendations for cartographic display design and future research are discussed.

Descriptors :   ACCURACY, ALPHANUMERIC DATA, BACKGROUND, CLUTTER, CONTRAST, DISPLAY SYSTEMS, FAILURE, IMAGES, MAPPING, MAPS, RADAR CLUTTER, REACTION TIME, SEARCHING, SYMBOLS, VERTICAL ORIENTATION, VISUAL PERCEPTION.

Subject Categories : Computer Hardware
      Human Factors Engineering & Man Machine System
      Cartography and Aerial Photography

Distribution Statement : APPROVED FOR PUBLIC RELEASE