摘要：Computer-Assisted Language Learning (CALL) as an example of artefact mediation has proved conducive to learners’ cognitive development (Chapelle, 2001; Warschauer & Healey, 1998). In second and foreign language teaching and learning, however, little attempt has been made to uncover the effect of vocabulary instruction through hypertexts and glosses on the learners’ growing knowledge from Vygotskian perspective. To this end, a total of 60 intermediate learners of English were asked to take a reading task and then answer a set of vocabulary questions both in the posttest and transcendence (TR) tasks. They were randomly assigned to the control, experimental (implicit) and experimental (explicit) conditions, and received different instructions. The results indicated that while both of the experimental groups benefited from the electronic mediation, the explicit group outperformed the implicit group. Moreover, the observation of enhanced and mediation-reduced performances in the TR tasks attested to the learners’ growing agency and independent functioning in innovative contexts (Lantolf, 2004; Poehner, 2008b). Hence, it was concluded that explicit instruction through hypertexts and glosses could significantly affect the learners’ vocabulary knowledge. On implication side, the computerized instruction of vocabulary through electronic scaffolding is suggested as a valid procedure to mediate L2 learners’ vocabulary growth.
