This study investigated whether source information attached to texts influences multiple-text comprehension about genetically modified (GM) foods-a controversial science topic. Participants in the experiment read two texts from two sources: an expert and/or a layperson. When the two texts presented different attitudes toward GM foods (Experiment 1), expert information facilitated intra-text comprehension. Moreover, expert information was better integrated with other information; when expert information was presented first, later information was less integrated with participants' understanding, and when expert information was presented last, it was more integrated. When the two texts presented common attitudes (Experiment 2), a similar pattern of effects was observed, but the effects were weaker than those in Experiment 1. Thus, expert source information has the potential to affect the comprehension of scientific information, and careful planning is required for effective risk communication.

Key words: source information, multiple-text comprehension, authoritative sources, information integration, risk communication