2.4. Procedure
The experiment consisted of two sessions with the first session lasting approximately 2.5 h and the second session lasting approximately 1.5 h. Prior to beginning the experiment, participants were asked to read and sign an informed consent form. They were told that the experiment was concerned with people's understanding of symbols used to communicate warning information.
In the first test session, a number of measures were obtained prior to, and following, the accident scenario training: ratings of agreement with attitudes reflecting perceived control, comprehension, and ratings of hazard and intent to comply (administered in this order). Following training, participants were given 10 min to fill-out a demographic questionnaire. They then completed the post-training series of test measures which was identical to the pre-training series. Participants returned 2 weeks later and completed a second series of post-training test measures.