Thesis (Ph.D.)--Northwestern University, 2002. / Includes bibliographical references.

This dissertation investigated the effects of technological mediation on second language (L2) learning, focusing, as a case study, on gains in listening perception of the subtle but important feature of pitch placement in Japanese. Pitch accent can be difficult to perceive for non-native speakers whose first language (L1) does not rely on pitch or tone as a distinctive feature, such as English (Wayland & Li, 2008). Pedagogically, Face-To-Face (FTF) interactions with native or near-native speakers are typically the most effective way to learn L2 sound system features due to social presence, but these interactions are not always possible because of physical distance. Mediation can facilitate these interactions, but it is unclear which type results in more learning gains. The current study compared three mediation types that vary in the information provided to the learner: audio-only (asynchronous), video (audiovisual asynchronous), and videoconferencing (audiovisual synchronous), as well as a fourth condition of videoconferencing which facilitated mutual eye contact. The lack of mutual eye contact in standard videoconferencing (due to the webcam being above the image of an interlocutor's face) can inhibit the perceived social presence (Bondareva, Meesters, & Bouwhuis, 2006). A pretest/posttest/delayed posttest design was used, which measured error rates and reaction times for a same/different discrimination task and a picture recognition task. The participants were English L1 speakers, with no prior study of Japanese. After the pretest, they received training in the form of two short lessons in beginner Japanese vocabulary and sentence building administered by a native speaking tutor, which did not explicitly address pitch placement, but used minimal pairs for this feature as vocabulary items. The lessons were followed by a posttest, and a delayed posttest one week later. The results showed that all four conditions succeeded in improving Japanese pitch placement detection, both immediately after and up to a week after the lessons. While an ANOVA revealed no main effect of mediation type, planned comparison results suggest videoconferencing without eye contact may lead to more gains in pitch placement perception than video. A surprising suggestion by the data was that videoconferencing with eye contact may lead to worse performance than the other mediation types. An exit survey detected the self-determination of the participants, and higher self-determination correlated with worse testing performance within the videoconferencing with eye contact condition. This suggests that the addition of eye contact increased the social presence of that condition to the point that it triggered Foreign Language Speaking Anxiety (FLSA) in the participants. Overall, this study highlights that lessons and tasks administered through mediation can be used to provide native speaker input for features that are important for listening and speaking, and this can effectively help learners attend to and learn these features.