There is a paucity of research examining the skills that contribute to reading comprehension for adults who struggle with reading, which includes one in six adults in the United States (Organisation for Economic Co-operation and Development, 2013). The current studies addressed some of the gaps in this literature.

Study 1 explored the Simple View of Reading (SVR), which postulates that reading comprehension is predicted by two component skills: decoding and linguistic comprehension (Gough & Tunmer, 1986). Participants included 392 struggling adult readers who were native speakers of English. The dimensionality of the SVR components was examined using confirmatory factor analysis. For the decoding component, a parsimonious latent representation inclusive of phonic decoding and word recognition provided good fit to the data. With respect to linguistic comprehension, the subcomponents of oral vocabulary and listening comprehension emerged as separable yet highly related constructs. A structural equation model showed that decoding and listening comprehension made significant unique contributions to reading comprehension, whereas oral vocabulary did not emerge as a significant unique predictor. Additionally, quantile regression analyses indicated that decoding, listening comprehension, and oral vocabulary exhibited significant unique effects on reading comprehension at low, average, and high levels of reading comprehension performance (.10, .50, and .90 quantiles), with decoding making the largest unique contributions.

Study 2 examined the influence of decoding, oral vocabulary, fluency, listening comprehension, background knowledge, and inferencing across different reading comprehension tests. Participants included 168 struggling adult readers who were native speakers of English. The explanatory effects of the predictors were estimated for three reading comprehension tests: WJ Passage Comprehension (WJ-PC), RISE Reading Comprehension (RISE-RC), and RAPID Reading Comprehension (RAPID-RC). Ordinary least squares regression analyses indicated that all predictors except for listening comprehension uniquely explained variance in WJ-PC scores, whereas significant unique predictors were limited to decoding and listening comprehension for RAPID-RC and only decoding for RISE-RC. Quantile regression analyses indicated that the effects of oral vocabulary and background knowledge differed across levels of WJ-PC performance, the effects of decoding and listening comprehension differed across levels of RAPID-RC performance, and the effect of decoding was stable across levels of RISE-RC performance.