- Vocabulary development and the role it plays in reading skills acquisition have received much less attention than decoding and comprehension strategies. There is a close relationship between vocabulary and comprehension; hence, individuals with poor vocabulary have difficulty understanding written text. Further, students with poor vocabulary knowledge read less and acquire fewer new words, while students with better vocabulary knowledge read more and improve their comprehension (the Matthew Effect). To prevent the Matthew Effect from taking hold, vocabulary assessment and instruction should become important components of reading programs for struggling readers with vocabulary problems. 2005 Taylor & Francis Group, LLC. All rights reserved.