The English Language Institute (now the School of Linguistics and Applied Language Studies) at Victoria University of Wellington has a long history of corpus-based vocabulary research, especially after the arrival of the second director of the institute, H. V. George, and the appointment of Helen Barnard, whom George knew in India. George's successor, Graeme Kennedy, also saw corpus linguistics as a very fruitful and important area of applied language research. This interest in corpus-based vocabulary studies led to an attempt to develop a test of receptive vocabulary size (Goulden, Nation & Read 1990). It became clear that a standard word family unit was needed, to enable consistency between different word families and different researchers. The result was a collaboration between two researchers in the School, Laurie Bauer and Paul Nation (1993). A series of steps must be followed in the creation of frequency-list based vocabulary size tests if the methodological difficulties of dictionary-based word sampling are to be avoided: (1) Develop a standard and reliable unit of word counting that suits the goals of the test; (2) Develop substantial word family lists that include virtually all the vocabulary to be tested; (3) Use corpora to arrange the word families in the lists into frequency levels; (4) Draw representative samples of word families from the lists so that no word frequency level is overrepresented or underrepresented in the samples; and (5) Decide on the test format and develop items for the tests. In many ways, the rate of progress through these steps has been determined by the availability of computer hardware and software. Because making word family lists is so time-consuming, for many years the 2,000 word families from the General Service List and the University Word List, the latter replaced by the Academic Word List (Coxhead 2000), were the only lists available. The availability of faster computers, larger corpora, data from the British National Corpus and a specially written word family building program (AffixAppender by Chris Andreae) enabled the creation of further lists. Even with all of this support, making word families was still time-consuming, and it was only in 2012 that the twenty-fifth 1,000 word families list was finished. In this article, the authors discuss the creation of the Vocabulary Size Test (VST) and the two directions recent research on it has taken: (1) bilingual versions of the test to use with non-native speakers of English; and (2) computerised versions of the test. Testing the vocabulary size of native speakers is also discussed. The authors conclude that the most pressing need at present is for a standardised vocabulary size test that can be used with very young native speakers of English and young non-native speakers who are not yet able to read in English.