An investigation of the effects of presentation format and time pressure on decision-makers performing tasks of varying complexities

The problem motivating this study is the lack of conclusive evidence supporting the use of graphics in business decision making. The phenomenal growth of the computer graphics industry and user interest suggests that graphics are effective in some instances. However, empirical verification of the existence of those situational factors and their relationships with each other remains a challenge. The significance of this research is in testing the effects of two situational factors, task complexity and time pressure. The purpose of this research is to determine whether graphics enhance performance when the decision maker is under certain time pressure. Viewing the importance of task complexity, a series of three experiments with varying complexities were conducted. A 2 x 3 design was used to test the effects of presentation format and time pressure in each experiment. Task complexity was implemented as the number of variables to be processed. Task content and task structure were also varied to contribute to different task complexities. Time pressure was implemented through imposing different time limits on task performance. Presentation format was measured by comparing tables with bar charts and line charts. Performance was measured primarily by the scoring of decision quality questions. Pilot tests were conducted to determine the cutoff points for different levels of time pressure. Undergraduate students were used as subjects, who performed the tasks during controlled experimental sessions. Graphics led to better performance only in the second experiment, which had a task of medium complexity. Increased time pressure generally decreased performance. However, performance deterioration was significant only among subjects using tables. Also, in one instance more time pressure led to significantly better performance among subjects using graphics. These results suggest that graphics may be better than tables when time pressure is high. The graphical advantage with increasing time pressure suggests that time pressure may have an impact on task complexity--an area worth further investigation. More research on time pressure is also needed.