Toward a domain theory in English as a second language

This paper demonstrates how domain theory development is enhanced by using both theoretical data and empirical data. The study explored the domain of speaking English as a second language (ESL) comparing hypothetical data on speaking tasks provided by an experienced teacher and by a certified ACTFL oral proficiency interview rater with observed data from scores on a computer-delivered speaking exam. While the hypothetical data and observed data showed similar patterns in task difficulty in general, some tasks were identified as being much easier or harder than expected. These differences raise questions not only about test task design but also about the theoretical underpinnings of the domain. The results of the study suggest that this approach, where theory and data are examined together, will improve test design as well as benefit domain theory development.