It has been widely recognized that learning and developing meaning of new words is dependent on the nature of linguistic input, memory, cognitive abilities as well as phonological, morphological and syntactic links formed by the learner. The interrelationship between language use and the construction of meaning of words is fundamental to language learning and language development. Reading comprehension tasks insufficient to promote the development of new vocabulary, as using complex cognitive processes need to be used in the development of new words. This paper demonstrates the use of verbalization of thought through think-aloud while engaging in language based tasks such as in reading comprehension as a way to encourage awareness of language cognitive processes, promote increased attention on meaning (micro and macro) and enhance the level of awareness which lead to these activities when given proper guidance may result in deeper processing and induce reactivity effect on the development of new vocabulary through reading. Through a deep review of literature on leaning and development of vocabulary based on the involvement load hypothesis. The paper proposes a particular focus on the issue related to the three components of the involvement load hypothesis (need, search, and evaluation) such as reading comprehension task that have related to the learning and development of vocabulary which have attracted the most attention in the issue of reactivity of think aloud on vocabulary development
