Factors affecting Observers' Accuracy when Assessing Credibility: The Effect of the Interaction between Media, Senders' Competence and Veracity.

The present experiment examined how the interaction between senders' communicative competence, veracity and the medium through which judgments were made affected observers' accuracy. Stimuli were obtained from a previous study. Observers (N = 220) judged the truthfulness of statements provided by a good truth teller, a good liar, a bad truth teller, and a bad liar presented either via an audio-only, video-only, audio-video, or transcript format. Log-linear analyses showed that the data were best explained via the saturated model, therefore indicating that all the four variables interacted, G2(0) = 0, p = 1, Q2 = 1. Follow-up analyses showed that the good liar and bad liar were best evaluated via the transcript (z = 2.5) and the audio-only medium (z = 3.9), respectively. Both the good truth teller and the bad truth teller were best assessed through the audio-video medium (z = 2.1, good truth teller, z = 3.4, bad truth teller). Results indicated that all the factors interacted and played a joint role on observers' accuracy. Difficulties and suggestions for choosing the right medium are presented.