Morphological knowledge, which refers to a conscious awareness of or the ability to use the smallest units of meaning in a language, may be important in learning to read English. However, the underlying nature of this construct is not well understood. A battery including nine morphological knowledge measures was administered to a fourth grade sample. In addition, two standardized vocabulary tests and three oral reading fluency tasks were included. Participants’ scores on a statewide reading comprehension test were also obtained.
A series of confirmatory factor analyses was conducted to explore the possibility that morphological knowledge may be divided into two or more subcategories. The role of method effects was then explored. The relation between morphological knowledge and vocabulary was also examined. Additional models designed to quantify the relations between morphological knowledge, vocabulary, oral reading fluency, and reading comprehension were included.
In all cases, a single-factor model of morphological knowledge was the preferred model. This indicates that the morphological tasks administered were all measuring the same construct, and that method effects were not playing a significant role in performance. The results of the analyses also showed that morphological knowledge and vocabulary are indistinguishable for fourth-grade students. When morphological knowledge and vocabulary were represented as a single latent variable, it accounted for a high and significant portion of the variance in reading comprehension.
