Accession Number:

ADA235947

Title:

The Effects of Line and Cell Failures on Reading and Search Performance Using Matrix-Addressable Displays

Descriptive Note:

Final rept.

Corporate Author:

HUMAN ENGINEERING LAB ABERDEEN PROVING GROUND MD

Personal Author(s):

• Lloyd, Charles J.
• Decker, Jennie J.
• Snyder, Harry L.

Report Date:

1991-04-01

Pagination or Media Count:

50.0

Abstract:

Reading and visual search speed and accuracy were used to evaluate the effects of simulated line and cell failures on a visual display. Five experimental variables failure type CELL, VERTICAL LINE, AND HORIZONTAL LINE, PERCENT FAILURE 0, 4, 8, OR 12 CELLS FAILED, display polarity LIGHT CHARACTERS ON DARK BACKGROUND OR DARK CHARACTERS ON LIGHT BACKGROUND, mode of failure FAILURES MATCH THE SYMBOLS OR FAILURES MATCH THE BACKGROUND, and matrix size 7 X 9, 9 X 11, OR 11 X 15 DOTS significantly affected performance of both the reading and search tasks. Additionally, many of the interactions among these variables were significant. The experimental results indicate that as the percentage of failures increased, performance systematically decreased. For failure levels of less than 4, little effect on performance was found. Performance increased as the size of characters increased. A 30 improvement in search time and a 7 improvement in reading time was obtained by using dot- matrix sizes larger than 7 x 9 pixels. In general, dark symbols presented on a light background negative contrast were read and searched for more quickly than light symbols presented on a dark background positive contrast.

Descriptors:

• *SEARCHING
• *DISPLAY SYSTEMS
• CELLS
• LIGHT
• FAILURE
• RATES
• ACCURACY
• TIME
• VARIABLES
• VERTICAL ORIENTATION
• DARKNESS
• BACKGROUND
• VISUAL PERCEPTION
• HORIZONTAL ORIENTATION
• VISUAL AIDS
• READING
• SIMULATION
• CONTRAST

Subject Categories:

• Computer Hardware
• Human Factors Engineering and Man Machine Systems

Distribution Statement:

APPROVED FOR PUBLIC RELEASE