(The University of Texas at Austin, 2016)
This dissertation explores the use of explicit phonetic instruction to students acquiring a second language (L2) in a new modality. Studies of spoken language L2 teaching have shown that learners can be trained to attend to phonetic cues in their new language and that explicit training is the most effective means by which to achieve this. Second-language learners of American Sign Language (ASL) struggle with fingerspelling comprehension more than many other aspects of language-learning; previous work has suggested that part of this challenge is due to the inability to observe and make use of phonetic cues present in the fingerspelling stream. The goal of this dissertation is to determine whether explicit training can benefit ASL learners for fingerspelling comprehension tasks.
Two studies assessed an explicit phonetic training program for ASL learners. An implicit fingerspelling training based on a popular ASL curriculum was also developed and used as a control with which to compare the effect of the explicit training. Designed based on a combination of interactions with L2 students in the classroom, descriptions of coarticulatory features in fingerspelling production, and studies of cues L2 students use to comprehend fingerspelling, the explicit training consisted of two main portions. The first detailed the properties of hold versus transition segments in fingerspelling; the second focused on phonetic variation in fingerspelling production.
The first study involved 18 third-semester ASL students in a five-week summer session. The second involved 80 students taking ASL III in a 15-week fall semester. In both studies, students were divided into two balanced groups based on grades earned in their previous ASL course. One group received the explicit training and the other, the implicit fingerspelling training. Pre- and post-tests involved a fingerspelling comprehension task with two experimental conditions and a control condition. In one condition, periods in which signers hold a letter posture were masked (transitions-only), and in the other condition, periods of transition from posture to posture were masked (holds-only).
Results from the first study revealed a strong effect of the explicit training across experimental conditions, though participants struggle most with the transitions-only condition. Results from the second study revealed a weaker overall effect of the explicit training, but a stronger interaction with the transitions-only condition, which the explicit training helped to address specifically. Taken together, results from both experiments reveal that explicit instruction is more effective in improving students’ fingerspelling comprehension scores. These effects are not ephemeral. With only one exposure to the training program, which lasts approximately 30 minutes, higher scores persist three and six weeks post training.