Noting that many prereading discussions lead teachers to "mis-estimate" students' prior knowledge about a particular topic, this paper describes the Pre-Reading Plan (PReP) designed to help both students and teachers become aware of what students already know about a specific topic. Following an introduction, the first portion of the paper explores why some frequently used teaching practices may fail to prepare students adequately to read their textbooks. The major part of the paper describes the three phases of the PReP activity, suitable for students in grades three through twelve in all subject areas, and requisite preparation for the activity. The final part of the paper discusses assessing student knowledge during the activity and provides examples of the PReP being used with several different types of reading material at different grade levels. (HTH)