Two experiments examined how cognitive resources are allocated to comprehension processes across two readings of the same scientific texts, In Experiment 1, readers read and later reread texts describing scientific topics, The results indicated that across readings, readers decreased resources allocated to proposition assembly, increased resources allocated to text-level integration, and expended a similar amount of resources to lexical access, Subjects who reread the texts after a week delay showed a similar pattern, except that they did not show the increase for text-level integration. Experiment 2 revealed a similar pattern of results with a moving window procedure, except that there was a significant decrease in resources allocated to lexical access across exposures. This experiment also indicated that the rereading speedup was greatest at sentence boundaries, suggesting that the prior exposure enabled readers to immediately process each word. Overall, the results are consistent with the claim that readers allocate proportionally more available resources to text-level integration during rereading because proposition assembly, which enables text-level integration, can be completed with fewer resources.Readers typically require more than one reading to understand a difficult text. Students, for example, often read their texts multiple times in hope of increasing their comprehension. Theoretically, multiple readings should facilitate comprehension because there would be more than one opportunity to acquire information from the text. With each reading, the comprehender would be able to further elaborate, repair, verify, and strengthen the existing text representation. Therefore, if a process or operation is not completed during one reading, it might be completed during a subsequent reading. Empirically, processing times have been shown to decrease across repeated exposures (Kolers, 1976;Levy & Burns, 1990;Rothkopf, 1968), whereas the memory and the comprehension of the material increases (Bromage & Mayer, 1986;Mayer, 1983;Rothkopf, 1968). Although this body of research indicates that reprocessing facilitates comprehension, the exact nature of how comprehension changes across multiple readings is relatively unknown.The goal of the present research was to examine the on-line comprehension of scientific texts across two readings of scientific texts. We chose scientific texts because college students normally have difficulty comprehending these types of texts, and therefore would benefit from additional readings. The question of primary