Affix Meaning Knowledge in First Through Third Grade Students.

Purpose: We examined grade-level differences in 1st- through 3rd-grade students' performance on an experimenter-developed affix meaning task (AMT) and determined whether AMT performance explained unique variance in word-level reading and reading comprehension, beyond other known contributors to reading development.

Method: Forty students at each grade level completed an assessment battery that included measures of phonological awareness, receptive vocabulary, word-level reading, reading comprehension, and affix meaning knowledge.

Results: On the AMT, 1st-grade students were significantly less accurate than 2nd- and 3rd-grade students; there was no significant difference in performance between the 2nd- and 3rd-grade students.