Link to publicationCitation for published version (APA): Hazenberg, S., & Hulstijn, J. H. (1996). Defining a minimal receptive second-language vocabulary for non-native university students: an empirical investigation.This study aimed to answer the question of how many words of the Dutch language, and which words, an adult non-native speaker needs to know receptively in order to be able to understand first-year university reading materials In the first part of this study, an assessment was made of the representativeness of a list of 23,550 words (lemmas), taken from a school dictionary, for a 42 million-word token corpus of contemporary written Dutch It was found that, using frequency as a criterion, text coverage substantially increased with up to 11,123 words (i e words occurring more than 100 times in the corpus), but not beyond In the second part of the study, an assessment was made of the representativeness of the same list of 23,550 words for a relatively small corpus of first-year university reading materials The percentage of tokens covered in this small academic corpus did not differ substantially from the percentage of tokens covered in the big corpus analysed in the first part The third part of the study consisted of the development and administration of a 140-item multiple-choice vocabulary test aimed at measuring test takers' receptive knowledge of 18,615 content words of the 23,550 word list This test was administered to (i) native speakers entering university as freshmen, (u) non-native graduate students, and (m) non-native prospective students taking a Dutch language entry examination test battery Extrapolations of the test scores showed that the average vocabulary size of these three groups of test takers was 18,800, 15,800, and 11,200 respectively It is concluded that the minimal vocabulary size needed for university studies is 10,000 base words Earlier Dutch studies, suggesting that knowledge of 3,000 or 5,000 base words would suffice, appear to have underestimated such a minimal vocabulary

Insights from scientific reading research only partially resonate in Dutch teaching materials for reading comprehension, and hence in the classroom. As an attempt to bridge the gap between science and educational practice, a design-based research was conducted in which four primary school teachers translated four researcher-provided design principles into practice. In two successive design cycles, the teachers designed and implemented lessons on informational text structures, under supervision of two researchers. The aim of the study was to gain insight into the viability of the design principles and into the level of support teachers need in order to become effective co-designers. Based on data from lesson artefacts, teacher logbooks, panel interviews and lesson observations, we found that the teachers experienced several implementation difficulties. These difficulties were partially due to the fact that there was a tension between two design principles, and that one design principle needed refinement. However, in most cases, the implementation difficulties could be explained by teachers’ limited pedagogical content knowledge. As a result, the teachers needed a high level of support, especially in text selection and revision. Teacher beliefs and habits also interfered with the implementation of the design principles, especially when it came to the importance of working with authentic texts, and teachers’ views on effective modeling.Our study raises questions about the feasibility of equal participation of researchers and teachers at the start of a DBR project, but also shows how DBR can successfully contribute to teacher professionalization if researchers provide adequate support throughout the design process.