Reading disabilities are the most common type of referral in schools. In non-RTI settings, evaluation of reading disabilities requires comprehensive individual evaluation of cognitive abilities and reading achievement (basic reading, reading fluency, and reading comprehension). The current study focuses on the measurement of reading comprehension skills. Miller and Maricle (2019) remind school psychologists that any psychological test must be understood within the context of the subtest's input - psychological processes required to engage in the task - and then output required to demonstrate one's response to the task. These notions also stimulated the research of Miciak et al. (2015) who explored differential decisions that may arise when two different subtests that measure the same construct are employed. In fact, Miciack and colleagues' study involve the Passage Comprehension subtest of the WJ-Achievement. This study aims to understand: (1) the correlational values between all Big Five and Short-Term Working Memory variables, (2) the performance of students with reading disabilities on Reading Recall compared to Passage Comprehension, (3) the cognitive predictors of performance on Reading Recall and Passage Comprehension within the entire standardization sample, and (4) the cognitive predictors of performance on Reading Recall and Passage Comprehension specifically within the first through fifth, sixth through eight, and ninth through twelfth grade groups. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]