BIAS AND ACCURACY IN ESTIMATES OF TASK DURATION

When asked to estimate the duration of various academic-type tasks (e.g., the time needed to complete a writing assignment, solve a series of problems, or read a manuscript), subjects demonstrated a marked tendency to trade accuracy in favor of minimizing cognitive effort in their selection of planning strategies. This tendency resulted in a drastic underestimation of the time required to complete the task. When estimating the total reading time of a manuscript, individual differences in reading speed were found to predict estimation accuracy. Given some experience reading the manuscript, fast readers switched from a low effort anchoring-type estimation strategy to a more effortful reading speed calculation strategy, whereas slow readers persisted in using an anchoring strategy, resulting in lower accuracy. Across all experiments, a meta-analysis revealed that global academic achievement, as indicated by grade point average (GPA), accounted for approximately 5% of the total variance in estimation performance. The consequences of planning accuracy on human performance are discussed. (C) 1995 Academic Press, Inc.