Have you ever found it difficult to read something because you lack knowledge on the topic? We investigated this phenomenon with a sample of 3,534 high school students who took a background-knowledge test before working on a reading-comprehension test on the topic of ecology. Broken-line regression revealed a knowledge threshold: Below the threshold, the relationship between comprehension and knowledge was weak (β = 0.18), but above the threshold, a strong and positive relation emerged (β = 0.81). Further analyses indicated that certain topically relevant words (e.g., ecosystem, habitat) were more important to know than others when predicting the threshold, and these keywords could be identified using natural-language-processing techniques. Collectively, these results may help identify who is likely to have a problem comprehending information on a specific topic and, to some extent, what knowledge is likely required to comprehend information on that topic.
Keywords: background knowledge; broken-line regression; content-area reading; knowledge-threshold hypothesis; reading comprehension.