Is Vocabulary a Strong Variable Predicting Reading Comprehension and Does the Prediction Degree of Vocabulary Vary According to Text Types.

Abstract The purpose of this study was to explore whether there was a significant correlation between vocabulary and reading comprehension in terms of text types as well as whether the vocabulary was a predictor of reading comprehension in terms of text types. In this regard, the correlational research design was used to explain specific research objectives. The study was conducted in Ankara-Sincan during the 2008-2009 academic years. A total of 120 students having middle socioeconomic status participated in this study. The students in this research were in the fifth-grade at a public school. Reading comprehension and vocabulary tests were developed to evaluate the students' reading comprehension and vocabulary levels. Correlation and bivariate linear regression analyses were used to assess the data obtained from the study. The research findings indicated that there was a medium correlation between vocabulary and narrative text comprehension. In addition, there was a large correlation between vocabulary and expository text comprehension. Compared to the narrative text comprehension, vocabulary was also a strong predictor of expository text comprehension. Vocabulary made more contribution to expository text comprehension than narrative text comprehension. Key Words Vocabulary, Reading Comprehension, Text Types. Reading comprehension is defined as a complex process in which many skills are used (Cain, Oakhill, & Bryant, 2004. As researchers (Palincsar & Brown, 1984; Samuels, 1983) report that there are many factors affecting this process, Snow (2002) argues that these factors are in relation to the reader, text, work, and context. Another variable seen as a main factor in reading comprehension and also related to these factors is vocabulary (Nagy, 1998 as cited in Bauman, 2009a). Reader factor includes prior knowledge, linguistic skill, and metacognitive awareness. The text factor encompasses genre, structure, and content of reading material; work factor includes aim of reading effort; and context factor involves socio-cultural environment and quality of reading instruction (Block & Parris, 2008; Israel & Duffy, 2009). Vocabulary is associated with all of these factors since all practices differentiate during the reading process for determining word meanings according to the reader's background knowledge, ability, metacognitive skills, and motivation. On the other hand, the text chosen according to the reading purpose will make the reader face texts that have different content and words. In that regard, the reader's learning and using these words, which she/he faces, are affected by the socio-cultural environment and the quality of reading instruction. Nagy and Scott (2000) contend that a child should know 90%-95% word meanings in a text to be able to derive meaning from the text. The National Reading Panel [NRP] (2000) reported that comprehension process cannot be defined regardless of vocabulary development and instruction in detail. In addition, even though Stahl and Nagy (2006) argued that the correlation between comprehension and vocabulary ranges from . 85 to . 95, other researchers argued that vocabulary is the strongest variable associated with comprehension, so scholars (Baumann, 2009b; Rosenshine, 1980) require focusing on vocabulary. As it was argued, there is a strong correlation between reading comprehension and vocabulary. Baumann (2009a) stated that all research about reading comprehension and vocabulary, including correlational, factorial, and readability, has showed that vocabulary is an essential component of reading comprehension. On the other hand, Ryder and Graves (1994) contend that a lack of vocabulary is one of the reasons for failure in school. In addition to this, Stahl and Fairbanks (1986) report that students who have wide vocabulary knowledge, get higher grades than students who have a lack vocabulary. From this perspective, it can be said that vocabulary is a distinction between good readers and poor readers. …