An ESL Index of Development

TL;DR: This article used the T-unit performance variable to measure the learner's proficiency in a second language acquisition, and found that the percentage of error-free T-units and the average length of error free T units proved to be the best discriminators among the five levels of ESL proficiency represented in this population.

Abstract: This paper is a report on the progress we are making in an attempt to establish a second language acquisition index of development. Such an index would be a developmental yardstick by which researchers could expediently and reliably gauge a learner's proficiency in a second language. Encouraged by the findings of an earlier pilot study, a more ambitious project involving the analysis of 212 compositions was undertaken. These compositions, written by university ESL students, were analyzed using several measures based on Kellogg Hunt's T-unit performance variable. Two measures applied in the analysis, the percentage of error-free T-units and the average length of error-free T-units, proved to be the best discriminators among the five levels of ESL proficiency represented in this population. In addition to a discussion of these results, included in this paper is a survey of L2 acquisition studies which have also employed T-unit length as a proficiency measure. Finally, an outline is offered of the studies currently being conducted in an attempt to further refine these measures.