Thirty second-grade boys--15 reading at grade level, 15 reading below grade level--were tested to determine whether children showing average and below average levels of reading achievement differed from each other in their mastery of basic language concepts and psycholinguistic abilities. They all met the criteria of (1) non-bilingual Caucasian race membership, (2) freedom from known auditory or visual defects, (3) normal emotional adjustment, (4) intelligence within the normal range, (5) a non-grade repeater and of the usual age of 2nd graders, and (6) matched socioeconomic status. Tests used during a 6-week period were the "Engelmann Basic Concept Inventory" and the "Illinois Test of Psycholinguistic Abilities." No significant difference was found to exist between the groups of average and below average readers for any of the test skill areas. (Author/MF)