As there is a general complaint about the poor lexical competence of students in non-English speaking universities, and as there is certainly no hope of remedying this by means of an increase in the academic staff, we have decided to measure our students' English vocabulary mastery (recalling of words) at the very start of their anglistic studies, so as to provide them with adjustable mastery-learning strategies, performable at computer terminals. In this paper we present the test's components and its measuring capacity. We use the 2000 most frequent English words, obtained by means of a merger of three objective frequency lists of about 1.000.000 words (the Brown Corpus, the Leuven Drama Corpus and the Lancaster-Oslo-Bergen Corpus), presented in a descending rank list; to each word the inflected forms and derivatives have been added. We also have combined this objective frequency with two subjective selections; the defining vocabulary of 2000 LDOCE-words (Longman Dictionary of Contemporary English, 1978) and 1500 words from J.C. Richards' Familiarity Count (1971). The words of these two lists that do not overlap with the frequency-words are considered as components of the test-corpus. The students who score below the means obtained for this test (in the Flemish part of Belgium + 111/150 in October 1980) get the opportunity to increase their vocabulary mastery by means of having to study a number of texts; they have to learn the new words (outsiders) in these texts and practise again the words they supposedly know. The analysis of the texts, the ordering according to the degrees of difficulty, the definition of outsiders, the construction of exercises on the outsiders and on the supposedly-known words between positions 501 - 2000 in the descending ranklist, the exercises on cohesion, cloze, polysemy - all these operations have been subjected to automation by computer, and the software developed thus far is operational. In the present paper the results obtained during the session of Mastery-Learning from October 1980 to March 1981 is presented, explained and discussed.