Department of Foreign Languages, Damavand Branch, Islamic Azad University, Tehran, Iran
Assessment is considered as one of the fundamental elements in the field of foreign language acquisition. In order for communication take place, adequate number of vocabulary is needed to be known by the learners. The salient role of vocabulary in the field of foreign language acquisition resulted in the publication of several hundreds of papers and dozens of books. Due to the dominant role of vocabulary in this area, this research investigated two variables considered to be effective in the learning and retention of second language vocabulary: word exposure frequency, and elaboration of word processing. Word exposure frequency that refers to the number of times the learners are exposed to a word in input was considered as one of the independent variables, and elaboration of word processing that refers to the quality and richness of processing new words in the textual input was considered as the second independent variable. Depth and richness of word processing were investigated based on the involvement load hypothesis offered by Laufer and Hulstijn (2001).