Publications

Abstract

Humans acquire word knowledge through producing and comprehending spoken and written language. Word learning continues into adulthood and knowledge accumulates across the lifespan. Therefore, receptive vocabulary size is often conceived of as a proxy for linguistic experience and plays a central role in assessing individuals’ language proficiency. There is currently no valid open access test available for assessing receptive vocabulary size in German-speaking adults. We addressed this gap and developed the German Auditory and Image Vocabulary Test (GAudI). In the GAudI, participants are presented with spoken test words and have to indicate their meanings by selecting the corresponding picture from a set of four alternatives. Here we describe the development of the test and provide evidence for its validity. Specifically, we report a study in which 168 German-speaking participants completed the GAudI and five other tests tapping into linguistic experience: one test measuring print exposure, two tests measuring productive vocabulary, one test assessing knowledge of book language grammar, and a test of receptive vocabulary that was normed in adolescents. The psychometric properties of the GAudI and its relationships to the other tests demonstrate that it is a suitable tool for measuring receptive vocabulary size. We offer an open-access digital test environment that can be used for research purposes, accessible via https://ems13.mpi.nl/bq4_customizable_de/researchers_welcome.php.

Abstract

Individual differences in using language are prevalent in our daily lives. Language skills are often assessed in vocational (predominantly written language) and diagnostic contexts. Not much is known, however, about individual differences in spoken language skills. The lack of research is in part due to the lack of suitable test instruments. We introduce the Individual Differences in Language Skills (IDLaS-NL) test battery, a set of 31 behavioural tests that can be used to capture variability in language and relevant general cognitive skills in adult speakers of Dutch. The battery was designed to measure word and sentence production and comprehension skills, linguistic knowledge, nonverbal processing speed, working memory, and nonverbal reasoning. The present article outlines the structure of the battery, describes the materials and procedure of each test, and evaluates the battery’s factor structure based on the results of a sample of 748 Dutch adults, aged between 18 and 30 years, most of them students. The analyses demonstrate that the battery has good construct validity and can be reliably administered both in the lab and via the internet. We therefore recommend the battery as a valuable new tool to assess individual differences in language knowledge and skills; this future work may include linking language skills to other aspects of human cognition and life outcomes.

Abstract

Experimental psychologists and psycholinguists increasingly turn to online research for data collection due to the ease of sampling many diverse participants in parallel. Online research has shown promising validity and consistency, but is it suitable for all paradigms? Specifically, is it reliable enough for individual differences research? The current paper reports performance on 15 tasks from a psycholinguistic individual differences battery, including timed and untimed assessments of linguistic abilities, as well as domain-general skills. From a demographically homogenous sample of young Dutch people, 149 participants participated in the lab study, and 515 participated online. Our results indicate that there is no reason to assume that participants tested online will underperform compared to lab-based testing, though they highlight the importance of motivation and the potential for external help (e.g., through looking up answers) online. Overall, we conclude that there is reason for optimism in the future of online research into individual differences.