Reading comprehension of scientific text: A domain-specific test of the direct and inferential mediation model of reading comprehension.

Reading comprehension is strongly associated with academic achievement, including science achievement. A better understanding of reading comprehension processes in science text might hold promise for improving science achievement in the long run. We tested the fit of the direct and inferential mediation (DIME) model of reading comprehension (Cromley & Azevedo, 2007) with 737 students in an introductory biology course required for majors. Participants completed multiple choice measures of biology-specific prior-topic knowledge, inference, reading strategy use, reading vocabulary, word reading fluency, and reading comprehension in small groups in our laboratory. Using structural equation modeling to test the fit of the DIME model to the data, we found excellent fit indices for all models. However, the original DIME model fit significantly worse than the measurement model, and a modified model that included a path from reading vocabulary to reading strategy use fit significantly better. Results from the modified model suggest that comprehension interventions for undergraduate students with biology majors might use preteaching to build topic knowledge. We discuss the need for future experimental studies to confirm the vocabulary-reading strategies link.