Karpen, S (2013) The role of task openness in forming completion time estimates. PhD thesis, Indiana University, USA.
Abstract
Of all of the biases to which humans are prone, the tendency to persist in making optimistic completion time predictions in the face of contrary evidence is one of the most insidious. This phenomenon, known as the planning fallacy, impacts nearly every area of life and is sometimes extremely costly. Originally, the planning fallacy was attributed to planners' tendency to focus on the specific features of the task at hand at the expense of external information (like past completion times and potential obstacles). Recent research, however, has argued that the planning fallacy can occur because planners dedicate too little attention the specifics of the task at hand. In the current work, we argue that the route by which the planning fallacy occurs is dependent on a task's openness. When a task is open and therefore must be completed in multiple settings, we argue that the optimistic completion time predictions result from too much attention to the task. When a task is closed and can be completed in one sitting, however, we argue that optimistic completion time predictions result from too little attention the task. We test this main--and several secondary--predictions across four experiments. In Experiment 1, participants predict the amount of time that will be required to complete a closed task after forming a careful plan or completing a control task. In Experiment 2, we follow a similar procedure with an open task. In Experiments 3a and 3b, we use one task that is administered in either an open or closed format. While we do not find support for our hypothesis that overly optimistic predictions for open and closed tasks rely on different mechanisms, we do find that the effect of careful planning is dependent on the type of prediction that participants make. Careful planning attenuated the optimism of time on task predictions (i.e. , the total amount of time spent at work on a task), but exacerbated optimism for completion time predictions (i.e. , the date on which a project would be finished).
| Item Type: | Thesis (Doctoral) |
|---|---|
| Thesis advisor: | Hirt, E R |
| Uncontrolled Keywords: | bias; cognitive psychology; completion time estimates; construction planning; operations research; optimism bias; scheduling; experiment |
| Index terms: | bias, estimate, experiment, construction planning, completion time, evidence, face, scheduling, operations research, psychology, optimism bias, planner |
| Subjects: | evaluation and assessment methods, cognitive psychology, psychology, operations research, profession, behavioral psychology, financial and cost management, design methods, construction planning, project controls, probability and distributions, data collection methods |
| Topics: | Research Practice, Design Practice, Organizational Design, Site Management, Cost Management, Roles and Professions, Time Control |
| Descriptive scope: | 5 PCTEA |
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