Effects of Long-Term Vocabulary Instruction on Lexical Access and Reading Comprehension

To examine the relationship between knowledge of word meanings and semantic processes, 27 4th-grade children were taught 104 words over a 5-mo period. Following instruction, Ss performed tasks designed to require semantic processes ranging from single word semantic decisions to simple sentence verification and memory for connected text. On all these tasks, instructed Ss performed at a significantly higher level than controls matched on pre-instruction vocabulary knowledge and comprehension. Thus, instructed Ss gave evidence both of learning word meanings taught by the program and of being able to process instructed words more efficiently in tasks more reflective of comprehension. Implications for vocabulary instruction and the role of individual word meanings in comprehension are discussed.