- Author
-
Yonemura, G. T.
|
Lister, K.
- Title
- Suprathreshold Visibility Meter to Directly Assess the Conspicuity of Office Tasks.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
- Sponsor
- Department of Energy, Washington, DC
- Report
-
NISTIR 89-4226
January 1990
32 p.
- Distribution
- Available from National Technical Information Service
- Keywords
-
visibility
|
conspicuity
|
contrast
|
legibility
|
office tasks
|
lighting
|
lighting requirements
|
task lighting
|
task performance
- Abstract
- An apparatus and methodology for evaluating the relative difficulty of visibility-related office tasks are described. The methodology differs from current evaluation techniques in that tasks are assessed in the laboratory as seen in the real world. The contrast of a reference task (5-bar grating) is varied until the conspicuity (how well the detail stands out from the background) is perceived to be equal to that of the sample task presented simultaneously. Data using typical alphanumeric materials encountered in commercial activities are presented. The investigation indicates that the apparatus and methodology give a good indication of the relative difficulty of real world sample tasks. Procedures for calibrating the task evaluators (observers) or the inclusion of a criterion correction factor in order to minimize differences in absolute values between evaluators are recommended.