Age-related differences in reliance behavior attributable to costs within a human-decision aid system

Objective: An empirical investigation was done to determine if there are age-related differences attributable to costs in reliance on a decision aid. Background: Costs of reliance on a decision aid may affect reliance on the aid. Older and younger adults may not perceive and respond to a dynamic cost structure equally or objectively. Method: Sixteen older adults (65-74 years) and 16 younger adults (18-28 years) performed a counting task with an imperfect decision aid. Two types of costs were manipulated: (a) cost of error (CoE) and (b) cost of verification (CoV). The percentage of trials in which participants agreed with the decision aid and did not perform the task manually was recorded as reliance. Results: Participants decreased their reliance as the CoE increased and increased their reliance with a lower CoV; however, they tended to under-rely on the decision aid. Younger adults tended to change their reliance behavior more than older adults did with the changing cost structure. Conclusions: Older and younger adults appear to interpret costs differently, with older adults being less responsive to changes in costs. Older adults may have been less able to monitor the changing costs and hence not adapt to them as well as younger adults. Application: Designers of decision aids should consider explicitly stating costs associated with reliance on the aid, as individuals may differ in how they interpret and respond to changing costs.