Appropriate Reliance Measurement

Description

Appropriate reliance measurement tests whether people who receive an AI system's advice follow it when it is right and keep their own judgement when it is wrong, and whether an explanation, or another aid such as a confidence score, moves them towards that pattern. It uses a two-step decision study on a classification task, the only kind Schemmer et al. define it for: for each task item the participant first decides alone, then sees the AI's advice, with or without the explanation, and makes a final decision, on a set of items with known correct answers drawn so that the AI is wrong on a known share of them. Only items on which the first decision and the advice disagree are counted, because when they agree the final decision cannot show which source the person relied on. Schemmer et al. define two rates over these items: relative AI reliance, the share of items with a wrong first decision and correct advice on which the person switched to the advice, and relative self-reliance, the share of items with a correct first decision and wrong advice on which the person kept their own answer. Comparing the two rates between an explanation condition and a control condition shows whether the explanation reduces under-reliance (rejecting correct advice), reduces over-reliance (accepting wrong advice) or merely raises agreement with the AI, which overall accuracy or agreement with the AI does not show on its own.

Example Use Cases

Explainability

An insurer considering highlighted claim features as an explanation for its fraud-flagging model runs a two-step study with its claims handlers on 40 past claims, with the model wrong on a quarter of them, comparing handlers who see the flag alone with handlers who also see the highlights. It adopts the highlights only if relative AI reliance rises without relative self-reliance falling, since higher acceptance of all advice, right and wrong, would show deference rather than better judgement.

A conservation charity whose volunteers identify bird species with help from an image classifier measures relative AI reliance and relative self-reliance separately for experienced birders and beginners, and for example-based and written explanations. It chooses which explanation to show each group from the results, because a volunteer's expertise changes how an explanation, especially a wrong one, shifts their reliance on the classifier.

Safety

A hospital whose safety case for a sepsis alert relies on ward doctors overriding wrong alerts, and whose workflow has doctors record their own escalation decision before the alert appears, runs a vignette study in that workflow, with and without the alert's explanation panel. Before switching the panel on, it reports relative self-reliance, and the share of wrong-alert cases that ended in a wrong decision, against the oversight requirement in the safety case.

Limitations

  • The rates describe behaviour on a task set built to contain many AI errors: Schemmer et al. drew equal numbers of items from each cell of the confusion matrix, which put the AI's accuracy on their 16 items at 50%. The study does not show how people rely on advice when errors are rarer, as they usually are in service, so it supports a claim about the conditions tested, not a direct estimate of over-reliance in deployment.
  • Only items on which the first decision and the advice disagree enter the two rates, so each rate can rest on a handful of items per person, and items on which the person and the AI are wrong together, the errors that oversight cannot catch, enter neither rate. Plan the sample around the expected number of disagreements, and report beside the rates the share of wrong-advice items that ended in a wrong final decision.
  • Asking for a decision before the advice is shown is itself an intervention. Guo et al.'s reanalysis of an earlier study found reliance closer to the appropriate level when people decided first than when they saw the AI's advice first, so a two-step study may show better reliance than a deployed system that presents the advice straight away.
  • The rates judge each decision by whether the advice turned out to be right, not by whether following it was the better bet given what the person could see. Guo et al. argue that this outcome-based definition mixes two failures, wrong beliefs about how often the AI is right and poor use of those beliefs, and treats a close call the same as an obvious one, so a low rate does not say which to fix.
  • Results depend on who takes part and on how good the explanations are. Morrison et al. found that participants' expertise changed how incorrect explanations affected their reliance, and that example-based explanations misled participants more than written ones, so a result from novices, or from explanations that were always correct, does not carry over to expert users or to explanations that are sometimes wrong.

Resources

Research Papers

Appropriate Reliance on AI Advice: Conceptualization and the Effect of Explanations
Max Schemmer et al.•Mar 27, 2023

Tags

Explainability Dimensions

Human Evaluation:
Properties:

Safety Dimensions