Abstract
This study explores the construct validity of speaking tasks included in the TOEFL iBT (e.g.,
integrated and independent speaking tasks). Specifically, advanced natural language processing
(NLP) tools, MANOVA difference statistics, and discriminant function analyses (DFA) are used
to assess the degree to which and in what ways responses to these tasks differ with regard
to linguistic characteristics. The findings lend support to using a variety of speaking tasks to
assess speaking proficiency. Namely, with regard to linguistic differences, the findings suggest
that responses to performance tasks can be accurately grouped based on whether a task is
independent or integrated. The findings also suggest that although the independent tasks included
in the TOEFL iBT may represent a single construct, responses to integrated tasks vary across
task sub-type.