This experimental study examined the efficacy of a multicomponent reading intervention compared to a business-as-usual comparison condition on the reading comprehension and content area vocabulary outcomes of adolescent students with low reading comprehension. We randomly assigned 9th-grade students with low reading comprehension to a researcher-provided intervention (n = 51) or a business-as-usual comparison (n = 49) group. Reading interventionists provided weekly instruction for 2 semesters (M = 114 hr) to small groups of students (M = 5). We estimated intervention effects for each outcome measure using repeated measures analyses of covariance (ANCOVAs) for measures of reading and vocabulary. Results indicated statistically significant differences between students in the intervention and comparison conditions on measures of vocabulary and on the Test of Sentence Reading Efficiency and Comprehension (TOSREC) and no differences on the Woodcock–Johnson III Passage Comprehension subtest. Repeated measures ANCOVAs indicated large effect sizes on vocabulary measures between intervention and comparison students on multiple-choice and free response items (η p2 =.16 and.19, respectively) and small effect sizes on the TOSREC (η p2 =.02).

The purpose of this study was threefold: to examine unique and shared risk factors of comorbidity for reading comprehension and word-problem solving difficulties, to explore whether language minority (LM) learners are at increased risk of what we refer to as higher order comorbidity (reading comprehension and word-problem solving difficulties), and to examine the profiles of at-risk LM learners compared with at-risk non-LM learners. At-risk (LM n = 70; non-LM n = 89) and not-at-risk (LM n = 44; non-LM n = 114) students were evaluated on foundational academic (word reading, calculation), behavioral (behavioral attention), cognitive (working memory, processing speed, nonverbal reasoning), and language (vocabulary, listening comprehension) measures in English. Results indicated listening comprehension was the only shared risk factor for higher order comorbidity. Furthermore, LM learners were 3 times more likely to be identified as at risk compared with non-LM learners. Finally, among at-risk learners, no differences were found on cognitive dimensions by language status, but LM learners had lower reading and listening comprehension skills than non-LM learners, with a relative advantage in behavioral attention. Results have implications for understanding higher order comorbidity and for developing methods to identify and intervene with higher order comorbidity among the growing population of LM learners.