Strategic and Interactive Signing Instruction Experiment

This randomized controlled trial (RCT) examines the effects of the Strategic and Interactive Signing Instruction (SISI) intervention on deaf children's expressive language development in signing (primary) and writing (secondary). The study compares two groups - an intervention group implementing SISI and a control group continuing their usual instructional routines without the intervention. The intervention group will include approximately 10 teachers, each working with 5-7 deaf children. These classrooms will implement the SISI intervention, which provides structured, language-centered supports designed to strengthen children's signing through explicit modeling, guided practice, and discourse-focused intervention routines. Schools that participated in the 2024-2025 nationwide pre/post study will be included in the intervention group for 2025-2026 if they choose to continue. The control group will likewise include approximately 10 teachers with 5-7 Deaf children each. These classrooms will continue with their standard practices without the SISI intervention. Schools newly joining the project in 2025-2026 will be assigned to this group. Child language data will be collected twice - fall 2025 (pre-test) and spring 2026 (post-test). Deaf children will complete three expressive language prompts representing major discourse types: personal narrative, informational report, and persuasive discourse. Their signed and written compositions will be analyzed using rubrics adapted from the National Assessment of Educational Progress (NAEP), focusing on growth in discourse-level skills. The study hypothesizes that deaf children in the intervention group will show greater gains in expressive signing and writing than their peers in the control group. This hypothesis reflects the expectation that a systematic, discourse-oriented language intervention offers stronger support for language development than typical intervention routines. This research aims to contribute to the evidence base on interventions that support deaf children's expressive language development. By examining child-level language outcomes from a discourse-focused intervention, the study will advance understanding of how structured language support can strengthen signing and writing development for deaf children.