Validated tests for language research with university students: Tests of vocabulary, general knowledge, author recognition, reading comprehension, reading frequency, attention check
We present five studies aimed at developing a new vocabulary test for university students. Such a test isuseful as an indication of crystallized intelligence and because vocabulary size correlates well withreading comprehension. In the first study, a list of 100 words based on Nation’s Vocabulary Size Test waspresented to 195 participants and compared to other tests of crystallized intelligence. Analysis suggestedthe presence of two distinct factors, which we interpreted as evidence for the possible existence of twotypes of difficult words: Unfamiliar words for general knowledge and unfamiliar words for specializedknowledge. In the subsequent studies we tried to develop vocabulary tests for each type of words, at thesame time trying out various reading comprehension tests to use as validation criterion. However, in thefinal study a high correlation (r =.82) was found between our two vocabulary tests, indicating that theymeasure the same latent factor, contrary to our initial assumption. Both tests have high reliability (r >.85) and correlate well (r > .4) with general knowledge, author recognition, and reading comprehension.As part of our research efforts, a collection of new and existing tests was used and (often) improved toverify the validity of the vocabulary tests. An exploratory factor analysis on all tests established 3 factors(text comprehension, crystallized intelligence, and reading rate), with the vocabulary tests loading on thefactor of crystallized intelligence, which in turn correlated with reading comprehension. Structuralequation modeling corroborated the interpretation. We end by providing an overview of the differenttests that were developed or improved throughout the studies. They are freely available for researchpurposes at https://osf.io/ef3s4/.