Focusing on the acquisition of semantic features and the relation between semantic and perceptual features, this study further tests the "semantic feature hypothesis," where a child acquires full adult word meaning component by component, and its complementary "correlation hypothesis," which claims that the source of these semantic features lies in underlying perceptual events. Dimensional adjectives were chosen because they can be defined in terms of perceptual features, such as height and length, which are amenable to experimental control. Forty children were administered four tasks at weekly intervals, and the results revealed a six-stage model of development in each child's pattern of response to "big,""little," and "long." The "semantic feature hypothesis" is systematically evaluated against the data, and it is concluded that those aspects of the hypothesis pertaining to the acquisition of semantic features are supported, but that aspects pertaining to the organization of features within semantic space need expanding to account for what happens with semantic space once a new feature is acquired and that linguistic development appears to be more than just a reflection of corresponding cognitive development. (EJS)