For the purposes of scoring essays written in a second language, two of the most important considerations are the intelligibility and the structural complexity of the writing. Various disadvantages are inherent in the use of clauses and/or sentences as a basis for analysing structure in written work; a more satisfactory technique was developed by Kellogg W. Hunt in America, using what he termed a ‘minimal terminable unit’ or ‘T‐unit’. This technique was applied in the scoring of the NFER open‐ended writing and speaking tests, which formed part of the battery of ‘Tests of English Proficiency forImmigrant Children’. During the development of these tests, the battery was administered to Asian children, for whom it was found that the average T‐unit length in writing and speech increased with increasing length of stay in Britain. (Average T‐unit length has been found by Hunt and O'Don‐nell to increase with age for children writing and speaking in their native language.) The results of the NFER testing indicated that much of the development of proficiency in both the speech and writing of the Asian children tested took place after three‐and‐a‐half years in Britain. (These findings were essentially a by‐product of test development, and therefore must be viewed with caution.).