Research indicates that prior knowledge is an exceptionally important determiner of reading comprehension. Many of the prereading strategies currently used to assist reading comprehension do not help teachers identify what students already know about a topic. In an effort to integrate instructional assessment with prereading instruction, the Pre-Reading Plan (PReP) was designed. PReP is a three-step procedure for teachers to use before assigning textbook readings. In the first phase, a key word or concept is given, and students tell what ideas freely come to mind. In the second phase, students are asked what made them think of their first responses. They listen to each other's explanations and interact. Phase three allows students to verbalize associations that have been elaborated or changed through the previous discussion. During phases one and three, three levels of prior knowledge are visible: much, some, and little prior knowledge. Based on responses during phase three, the teacher will be able to judge whether the students' concepts are sufficiently close to those presented in the text to permit comprehension and learning of the material. (HTH)