Diagnostic and Developmental Potentials of Computerized Dynamic Assessment (C-DA) for L2 Vocabulary

Computerized form of dynamic assessment (C-DA) has recently gained a foothold in second/foreign language (L2/FL) context. Inspired by Vygotskian socio-cultural epistemology, C-DA integrates assessment and instruction through providing learners with attuned electronic mediations. This study applied C-DA to assess and instruct L2 learners’ vocabulary knowledge in reading comprehension tasks. Following a pretest–posttest control group design, the study included 70 participants who were randomly selected based on non-probability sample design from 125 students at the outset of the study. The experimental group (N=35) received the C-DA mediation and the control group (N=35) underwent a traditional, unmediated instruction. To be able to simultaneously assess and promote the learners' knowledge of vocabulary, a software program was designed, which could present a number of reading passages and offer strategically a wide range of hierarchically-based electronic mediations. The results of paired and independent samples t-test revealed significant improvement of the DA group. The information obtained from the learners’ learning potential score (LPS) helped diagnose their emerging abilities, which evidenced that learners with equal actual scores in their independent performance had different mediated scores, gained score, and LPS. Moreover, the comparison of learners’ non-dynamic assessment (NDA) and DA scores through both paired and independent samples t-test attested to the diagnostic function of C-DA in surfacing learners’ underlying potential, a finding which has direct implications for L2 vocabulary assessment and development in EFL context.