==== Definition ====
The strong effect that background knowledge has on reading comprehension is one of the most stable findings in all of cognitive psychology (Paris & Stahl, 2005). Even early reading researchers from Gates (1931), Huey (1908), and Gray (1939) noted the relationship between background knowledge and reading.

Background knowledge, knowledge a reader, network or environment brings to any text or learning situation (Alexander,  1992;  Anderson & Pearson,  1984) explains the greatest amount of variance in measures of comprehension, after accounting for the ability to decode text. 

If you know about a topic you understand more complicated texts about a topic. ( Means & Voss,  1985). In fact reading researcher suggest at least three distinct areas of background knowledge as they construct meaning from informational text (Anderson & Pearson,1984):
  *  general world knowledge
  *  prior subject-matter knowledge,
  *  prior knowledge of text structure


=== Vocabulary and Background Knowledge ===

===== What Do Good Readers Do With Background Knowledge =====

  * Organize background knowledge of topic and text structure with what they read (Graesser et al,  1994);
  * Make intertextaul Links (Hartman, 1999; Kintsch & van Dijk,  1978);
  * Use text structure to skim and scan (Englert & Hiebert,  1984);
  * Use background knowledge to monitor comprehension (Duke & Pearson, 2002)
  * Use background knowledge to question texts. (Paris, Wasik, & Turner,  1991; Duke & Pearson, 2002)
  * Use background knowledge to for fx-up strateggies (Paris, Wasik, & Turner,  1991; Duke & Pearson, 2002)

===== Background Knowledge in the Classroom =====
  * Use KWL charts to have students monitor how background knowledge changes and grows.
  * Provide concept maps as pre and post measures of knowledge growth
  * Use vocabulary quizzes and questions as proxies for growth in the classroom