This article examines the reliability and validity of the construct, mode of acquisition (MOA). The MOA of a word denotes the way in which the word's meaning is learned. A word's meaning can be acquired perceptually, linguistically, or by some combination of both. In Experiment 1, 26 student volunteers from third year special education courses rated 566 words, taken from reading texts in elementary school, on MOA. Our findings show that MOA ratings gradually change over grades, shifting from mainly perceptually acquired word meanings in Grade 1 texts to mainly linguistically acquired concepts in Grade 6 texts. In Experiment 2, 34 educational professionals completed a list on MOA, concreteness, or imageability. Judgments on the MOA proved to be different from judgments of concreteness and imageability. We suggest that the increasingly linguistic character of word meanings contribute to explaining some of the reading difficulties of deaf children.