Background knowledge can facilitate comprehension and vocabulary learning during extensive reading. Related to, but often different from, lexical knowledge, it supports cognitive processes such as inference, integration, and comprehension monitoring by freeing up resources. A study done in an L2 EAP ER program in Japan looked at its effects.
Vocabulary familiarity is highly connected with reading comprehension, with correlations (r= .50 to .7) typically observed in L1 reading (Hirsch, 2003; Perfetti et al., 2013). Research with L2 learners has shown that familiarity with around 98% of running words in a text are needed for vocabulary not to impede comprehension (Hu & Nation, 2000) and that more frequent encounters with unknown lexical items lead to better learning, especially when no activities are in place to alter the quality of those encounters (Nation, 2015). Research has suggested that better enjoyment of reading and learning results from better comprehension. Reading comprehension, however, is a complex construct resulting from a wide range of knowledge, skill, and strategy applications (Scarborough, 2001), in addition to working memory and proficiency. A reader uses these to combine word-level processes, general cognitive processes, and higher-level comprehension processes to create a situation model of the content (Perfetti et al., 2013). While background knowledge is closely associated with lexical knowledge, the two are not always the same and its role warrants attention as various skills related to it (vocabulary flexibility, inference, integration, and comprehension monitoring) are crucial for comprehension (Cain, 2013). This presentation will briefly review the role of background knowledge in comprehension before reporting on a study done at an EAP program Japan investigating the role of background knowledge and comprehension within an extensive reading program. During a self-selected ER program, two randomly assigned groups of students were asked to read the same reader. Students were assessed on their knowledge of critical background knowledge with survey questions and test items. Half of the students were then given a short boost of instruction providing/reminding them of important background knowledge. After reading the book, students were given a more detailed post-test checking for comprehension and vocabulary learning. The study found evidence of differences in background knowledge, but did not find a mediating effect for that knowledge in better comprehension (as measured by better recall of details of the text) or vocabulary learning from the text. Overall, student comprehension and vocabulary learning from the text was not as high as expected given the level of the passage and proficiency of the students. Finding ways to deal effectively with differences in background knowledge and essential domain vocabulary may affect the reader's experience and learning from texts, something of a growing concern as students are increasingly engaging with non-fiction expository texts.
