Extensive reading for a 9,000-word vocabulary: Evidence from corpus modeling

This paper contributes to a research program within extensive reading (ER) and Reading in a Foreign Language using corpora to simulate ER input to develop vocabulary through incidental learning to 9,000 words. This helps researchers/teachers evaluate ER. If corpora indicate no ‘pathway’ from smaller to larger vocabulary sizes through authentic ER input, with vocabulary recurrence rates sufficient for incidental learning, then graded readers or other pedagogy appear essential. Studies offer different conclusions due to modeling issues. This study replicates previous research on a larger corpus of general fiction, with improved modeling. For every vocabulary size, a substantial amount of comprehensible fiction is found, with enough repetition of vocabulary from subsequent levels that pathways from smaller to larger vocabulary sizes are possible without graded readers. Prior estimates of approximately 3 years to acquire 9,000 words at 1 hour a day are underestimates, with modeling indicating 2 hours a day would be required.