Increased scrutiny of educational proficiency targets has intensified the urgency for educators to identify measurements that indicate students' likelihood of eventual achievement in reading. This regression analysis explored the relationship between nonverbal ability in kindergarten as measured by the Naglieri Nonverbal Ability Test (NNAT) and eventual third-grade achievement in reading and writing as measured by the Missouri Assessment Program (MAP). Naglieri and Ronning (2000) found a range of correlational "r" values from 0.49 to 0.56 when comparing NNAT results to results from the Stanford Achievement Test 9 (SAT-9) in reading when tested concurrently at various grade levels. The present research examined data from two cohorts of students (n = 794, 795) and produced correlational "r" values of 0.50 and 0.44 with a four-year span between assessment administrations. These "r" values are similar to those found in other research comparing ability with reading achievement in the early childhood years. Furthermore, this study examined the results of multiple regression analysis between seven student demographic subgroup categories and identified the NNAT's ability to predict MAP achievement for each group. [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://www.proquest.com/en-US/products/dissertations/individuals.shtml.]