A Comparison of Inter-Symbol Contrast Ratios for Segmented Digital Readouts.
Abstract
Twelve subjects viewed a Chicago Miniature segmented digital readout display to compare symbol legibility under two inter-symbol contrast ratio conditions - 4:1 and 2:1. Using two test lamps designated A and B, a series of test trials was presented under both conditions randomly intensifying the three horizontal segments of symbol A to determine the effect, if any, on symbol legibility. The stimuli consisted of numerical digits; digits 3, 5, and 9 were presented at symbol A and digits 0-9 at symbol B. Performance data were based on subject's digital readout error scores. From evaluation of the performance data, it was concluded that the 4:1 inter-symbol contrast ratio was significantly better than the 2:1 condition and that there was no apparent 'aural effect' degrading performance under either condition. Additionally 'five' was significantly misidentified more often--primarily as a 'nine'. This identification error was attributed to insufficient distinguishing cues between the two digits. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1977
- Accession Number
- ADA050630
Entities
People
- Jane M. Kline