How heuristic credibility cues affect credibility judgments and decisions.

We investigated how heuristic credibility cues affected credibility judgments and decisions. Participants saw advice in comments in a simulated online health forum. Each comment was accompanied by credibility cues, including author expertise and peer reputation ratings (by forum members) of comments and authors. In Experiment 1, participants' credibility judgments of comments and authors increased with expertise and increased with the number of reputation ratings for supportive ratings and decreased with number of ratings for disconfirmatory ratings. Also, results suggested that the diagnosticity (informativeness) of credibility cues influenced credibility judgments. Using the same credibility cues and task context, Experiment 2 found that when high-utility choices had low credibility, participants often chose alternatives with lower utility but higher credibility. They did this more often when less utility had to be sacrificed and when more credibility was gained. The influence of credibility and utility information on participants' choices was mediated by their explicit credibility judgments. These findings supported the predictions of a Bayesian belief-updating model and an elaboration of Prospect Theory (Budescu, Kuhn, Kramer, & Johnson, 2002). This research provides novel insights into how cues including valence and relevance influence credibility judgments and how utility and credibility trade off during decision making. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Effects of intelligent advanced warnings on drivers negotiating the dilemma zone.

OBJECTIVE: We investigated whether intelligent advanced warnings of the end of green traffic signals help drivers negotiate the dilemma zone (DZ) at signalized intersections and sought to identify behavioral mechanisms for any warning-related benefits. BACKGROUND: Prior research suggested that warnings of end of green can increase slowing and stopping frequency given the DZ, but drivers may sometimes respond to warnings by speeding up. METHOD: In two simulator studies, we compared six types of roadway or in-vehicle warnings with a no-warning control condition. Using multilevel modeling, we tested mediation models of the behavioral mechanisms underlying the effects of warnings. RESULTS: In both studies, warnings led to more stopping at DZ intersections and milder decelerations when stopping compared with no warning. Drivers' predominant response to warnings was anticipatory slowing on approaching the intersection, not speeding up. The increased stopping with warning was mediated by increased slowing. In Study I, anticipatory slowing given warnings generalized to green-light intersections where no warning was given. In Study 2, we found that lane-specific warnings (e.g., LED lights embedded in each lane) sometimes led to fewer unsafe emergency stops than did non-lane-specific roadside warnings. CONCLUSION: End-of-green warnings led to safer behavior in the DZ and on the early approach to intersections. The main mechanism for the benefits of warnings was drivers' increased anticipatory slowing on approaching an intersection. Lane-specific warnings may have some benefits over roadside warnings. APPLICATION: Applications include performance models of how drivers use end-of-green warnings, control algorithms and warning displays for intelligent intersections, and statistical methodology in human factors research.