A reader' background knowledge can influence reading comprehension (Carrell, 1983, Carrell and Connor, 1991). Background konwledge includes all of the experiences that a reader btings to text: life experiences, education experiences, knowledge of how texts can be organized rhetorically, konwledge of how one's first language works, knowledgd of how the second language works, and cultural background and knowledge. Reading comprehension can be significantly enhanced if background knowledge can be activated by setting goals, asking question, making prediction, teaching text structure, and so on. If students are reading on an unfamiliar topic, you may need to begin the reading pfocess by building up background knowledge.
An interesting concept to consider related to the role of background knowledge is the negative influence it may have. Incorrect background knowledge can hinder comprehension. For example, some reader may have miscooneceptions about how AIDS is contracted. Some may believe that you can get AIDS by kissing or swimming in a pool. These misconception may interfere with a reading passage on AIDS, and you may have to correct the background knowledge throungh a prereading activity before reading comperhension can be achieved.