Professional development and signed literacy instruction: evidence from a multiple-baseline design

This study examined whether professional development can translate a signed literacy instruction framework into high-fidelity classroom practice. Four K-3 teachers in an ASL/English bilingual program received a 2-day training followed by bi-weekly virtual coaching; entry into training was staggered in a non-concurrent multiple-baseline single case design. Teachers' use of indicators of signed literacy instruction was scored for at least 7 baseline and 2 intervention instructional units per teacher. Visual analysis showed near-zero fidelity during baseline and an immediate jump to 45%-60% on the first post-training unit, with 3 teachers accelerating to 80%-90% and 1 maintaining at 60%. Log response-ratio effect sizes ranged from 2.04 to 3.72, confirming large, consistent gains. Social validity interviews indicated that teachers valued the instructional framework, found it feasible, and planned to expand its use the following year. These findings show a functional relationship between SISI professional development and teachers' implementation of signed literacy instruction. They emphasize the value of professional development and suggest that signed literacy instruction can be embedded in early elementary curricula to promote deaf children's signing skills.