The primary objective of the study presented here was to test the following hypothesis: A more
accurate estimate of English proficiency in any specific language domain (speaking, for instance) can be attained by assessing skills not only in that domain but in other related domains as well (listening, for instance). Because the four domains of language are related in complementary ways, a measure of ability in one (e.g., listening) can, when used in conjunction with a measure of the target ability (e.g., speaking), add nuance/depth and accuracy to the measurement of the target ability