Portland State University. Systems Science Ph. D. Program
Robert E. Good
Date of Award
Doctor of Philosophy (Ph.D.) in Systems Science
3, xi, 216 leaves: ill. 28 cm.
Decision making -- Evaluation, Information visualization, Computer graphics
Words need a context to be understood. Visual patterns also need a context to convey their meaning. When patterns represent quantities in business graphics, decision makers (DMs) depend on contrasting visual contexts to discern patterns and discover relationships. Depending on the context in which DMs see trends, differences between two trends may point to a problem, to continuity, or to an opportunity. Can enhancing the context in computer graphics help DMs visualize problems? To answer this research question, three experiments were done in the field on computer graphics. One hundred five DMs tried 17 different contexts for time-series trends displayed on a microcomputer monitor. The research objective was to find out whether changing the context in graphics affected the decision efficiency (accuracy/response time) of DMs in determining relationships among trends. Essential for measuring the effect were interactive computer programs that displayed random trends in graphics of differing contexts, collected the DMs' answers to questions about the trends, and graded 1133 graphics based on the answers, response times, and trend data. The experimental results supported the hypothesis that computers can enhance the visual context surrounding time-series trends so that DMs can better visualize problems. Results were based on comparisons of DMs' decision efficiencies between trial graphics with differing contextual enhancements and based on answers to questions about the trial graphics. The results were tested with nonparametric statistics at the 0.05 significance level. Specific findings were: (1) Computer-supplied forecasts, as an enhancement, significantly helped DMs discover differences among trends. (2) Although not statistically significant, stratified presentation of trends and fading chartjunk tended to increase DMs' efficiencies. (3) Adding two colors, as an enhancement, made no difference in efficiency over black and white. (4) Paired trends in windows did not affect efficiency significantly. (5) Sequentially traced trends and composites of enhancements did not affect efficiency significantly. (6) DMs preferred stratified trends most and had the most confidence in graphics with fading context. They least liked and had the least confidence in black-and-white graphics.
Brock, Floyd James Jr., "Enhanced Computer Graphics for Decision Makers" (1986). Dissertations and Theses. Paper 1238.