were found, both on the short and long term. There are a number of substantial differences between narrative and expository reading comprehension. Overall, expository texts are thought of to be more difficult and require different reading skills. As compared to information stated in expository texts, the information presented in narrative stories often resembles experiences students have in everyday life (Graesser et al., 1994). These experiences include word knowledge, world knowledge, and experiences with inferences typical for narrative texts. Information stated in expository texts often does not resemble everyday life events. These texts have a larger number of unknown words, students have less world knowledge which they can use in integrating new information, and understanding these expository texts often requires different, more difficult, types of inferences (Graesser, McNamara, & Louwerse, 2003). In comparing words used in narrative and expository texts, Gardner (2004) concluded that in expository texts a greater proportion of words at the more specialized vocabulary levels (i.e., academic vocabulary) is utilized and that as a result of that, these expository texts place more lexical demands on students in general. Through the WTTI intervention, including several lexical assignments, students in the experimental group received more training in how to read expository texts for comprehension and how to handle these lexical demands. Based on the results of the present study, we can argue that training word-to-text integration skills and subsequently creating a visual representation of the text especially benefits expository reading comprehension. Future research, however, is warranted to adequately support this statement. Finally, additional analyses showed that the effects of the WTTI intervention were equal for all students, irrespective of pretest levels of decoding, vocabulary, and reading comprehension. Based on these results, we can conclude that the WTTI intervention is effective in improving intervention based reading vocabulary and expository reading comprehension skill for a broad range of students.
Results from the present study have several important implications for both education and research. First of all, with the current study we showed that vocabulary and reading comprehension go hand in hand. One intervention, with a focus on word-to-text integration, can be implemented in the school curriculum to improve both (specialized) reading vocabulary and expository reading comprehension skill. Expository texts are often used in school settings when teaching students for example about history, geography, or science. Incorporating a word-to-text integration focused approach during these sessions, might not only lead to an increase in knowledge on these specific subjects, but also to an increase in vocabulary and comprehension skill in general. Word representations created during these sessions are proven to be stable and long-lasting. Secondly, we have shown that the WTTI intervention can be implemented in classrooms relatively easy. With only a short training and some additional coaching, teachers were able to implement the intervention and improve students’
is appropriate for a broad range of students and can therefore be implemented as a whole- class based approach.
In future research the current results should be elaborated on in a number of ways. In the present study, teachers in the experimental condition were trained and coached in the use of think aloud procedures, cooperative learning, and student differentiation. The additional professional development might have contributed to the treatment effects, especially if the training has led to differences in teaching behaviors throughout the day. Slavin et al. (2008) have shown that programs designed to change daily teaching techniques in combination with change of the curriculum are more effective, as compared to programs focused on changing techniques or curriculum alone. Future research on the effects of word-to-text integration interventions would benefit from including a control group in which these teaching techniques are trained but changes in the curriculum are not implemented and a control group in which changes in the curriculum are implemented without training these teaching techniques. Regarding the stable enhancement of intervention based reading vocabulary, the results of the present study raise a number of questions. First, with the current study, we have shown that students in the experimental condition improved their reading vocabulary breadth. However, no measures of depth were administered. In the future, it would be interesting to examine the effects of the WTTI intervention on intervention based vocabulary depth. In addition, more from an experimental angle, insights in how often students have to encounter a specific word in order to learn it, would be highly relevant, especially in improving the WTTI intervention. Second, based on previous research, it has been suggested that incidental word learning provides the primary means of vocabulary acquisition, especially beyond the primary grades of elementary school when students have acquired decoding skills and start to read more independently (Wagner et al., 2007). In the current study, we did not incorporate any incidental word learning strategies in the intervention. Future research would benefit from examining the possibility of including these strategies in the WTTI intervention, in order to improve, in addition to specific reading vocabulary, generalized vocabulary.
With respect to reading comprehension, we have shown that the WTTI intervention has a positive effect on short-term expository reading comprehension skill. It is important to keep in mind that the expository reading comprehension test included only one reading passage at each time point and that for one passage test reliability was questionable. Future research, examining the impact of word-to-text integrating intervention, would benefit from including more expository and narrative passages per time point with better test reliability. Based on results from the current study, it remains unclear how students in the experimental condition changed their reading behavior as compared to students in the control condition. To answer this question, more experimental research is warranted. In addition, due to ethical reasons, students in the