The Interplay between Text based Vocabulary Size and Reading Comprehension of Turkish EFL Learners
Recently, there has been a burgeoning interest in the relationship between reading comprehension and vocabulary knowledge, and this emanates from the fact that academic achievement is closely related to reading performance (Adamson, 1993; Collier, 1989) As might be expected, the best way to learn new vocabulary items is considered to read, and knowing extensive vocabulary is a prerequisite to understand a text (Eskey, 2005) Therefore, it is necessary to scrutinize breadth of a person's vocabulary as a predictor of reading comprehension on a regular basis to reach a consensus about the amount of vocabulary needed by an L2 learner for a reasonable comprehension of expository texts. However, although there have been several studies evaluating the relationship between reading comprehension and vocabulary knowledge in general, these studies do not include Turkish learners of English as participants whose native language is not etymologically related to English. Scholars, on the other hand, acknowledge that English as a foreign language (EFL) learners feel the burden of reading in an L2 twice as much as their counterparts, L1 readers, do, and success is difficult to come by without being a skilled reader (Carrell Grabe, 2002) For that reason, the present article aims to investigate a perennial concern, that is, the relationship between the vocabulary coverage and reading comprehension of a group of Turkish EFL learners because first reading is an indispensable skill for academic achievement and second reading comprehension is directly linked to learners' vocabulary knowledge. After a brief summary about reading comprehension and vocabulary knowledge as a reciprocal process, the article aims to discuss what percent of the vocabulary items should be known in an expository text to comprehend it, and the corresponding vocabulary size will be discussed by analyzing the sizes suggested in the studies of Nation (2006) and Laufer and Ravenhorst Kalovski (2010).A Reciprocal Process: Reading Comprehension and Vocabulary SizeReading is delineated as "the process of receiving and interpreting information encoded in language form via the medium of print" (Urquhart Weir, 1998, p. 22) As stated by Linan Thompson and Vaughn (2007) and Grabe and Stoller (2002) reading comprehension is the main purpose for reading, and this purpose underlies and supports most of the other purposes for reading. However, since reading involves cognitive processes, reading comprehension is an invisible concept that can only be inferred (Bernhardt, 2011) Moreover, reading comprehension presents some challenges for learners as many students consider reading a boring and difficult task. When the complexity of reading is considered together with its purposes and properties, it becomes clear that reading is complex for both teaching and learning.In addition to the complexity of reading, it is unarguably clear that the relationship between vocabulary size and reading comprehension is reciprocal. While some scholars focus on the effects of vocabulary size on reading comprehension in their studies, some others study the effects of reading comprehension on vocabulary size (Eskey, 2005; Hu Nation, 2000; Nation, 2001; Nation Angell, 2006) According to Rumelhart (1977) and Stanovich (1980) in evidence based reading models, bottom up processes such as word recognition and lexical access go hand in hand with top down processes such as integrating background knowledge and processing strategies. Readers need automaticity in both word recognition and lexical access (Walter, 2003) From a lexical perspective, Anderson (2009) and DeKeyser (2007) summarize this long learning process as a path from understanding a word's meaning to learning a major meaning of a word, and then learning many aspects of a word's meaning and use. Therefore, the faster a reader recognizes a word, which is linked to learners' vocabulary knowledge and automaticity, the better reading comprehension will take place.