Counts of register features have produced useful data on varieties of
written English and on differences between writers of differing writin
g and language proficiency. This article reports an attempt to extend
this procedure to an evaluation of the same foreign-language writers a
t two different stages. It shows that the procedure can differentiate
the products of developing writers at two relatively close points in t
ime, and that a more detailed examination of significant changes can b
e revealing about patterns of learning. The major changes were from fe
atures of spoken English to those more typical of formal writing, both
in surface detail and in more fundamental characteristics. There was
less change in complexity of construction or variety of vocabulary. Im
proved correctness in the structures used was balanced by errors in ne
w structures being attempted. The subjects had been discriminating in
their acceptance of academic style and actively sensitive to genre and
other requirements.