A review of the literature was conducted to summarize how characteristics of individual readers help to determine the nature and quality of their comprehension of specific texts and to discuss how this knowledge might be used by teachers to promote effective reading in their classes. Three dimensions of readers were identified as being causally related to comprehension. First, readers differ in terms of what they know. Readers who are highly familiar with the topic about which they are reading and or the organizational structure of the text they are reading comprehend better than those readers who are less familiar with the topic and organizational structure. Second, readers differ in terms of the cognitive skills and strategies they have available for use while they are reading. Some readers have fully internalized a given strategy, such as predicting what should logically come next, others have done this only partially, and still others lack this strategy altogether. Third, readers differ in terms of their motivational orientations toward the text. Readers' attitudes about their comprehension abilities can be at least as important in determining their comprehension of specific texts as their actual comprehension abilities. Teachers who recognize the transactional nature of reading comprehension understand that characteristics of individual readers differentially influence their reading comprehension. These are the teachers who will be able to create reading lessons and programs to serve the varied needs of each reader in their classrooms. (One hundred twenty-nine references are included.) (MG)