Design and evaluation of a Swahili tangible letters reading application for learners with intellectual, developmental, and learning disabilities in Tanzania

Background Reading acquisition is particularly challenging for learners with intellectual, developmental, and learning disabilities (IDLD), especially in resource-constrained educational contexts. Affordable and engaging instructional technologies are needed to support inclusive literacy instruction in developing countries. Objective This study reports the novel design and evaluation of a low-cost, gamified tangible user interface (TUI) application incorporating optical character recognition (OCR) to support Swahili reading instruction for learners with IDLD in an inclusive Tanzanian school setting. Methods Guided by Gagne’s instructional design principles and developed using agile methods, the system was evaluated using a single-case experimental design with a multiple-baseline design across six learners with IDLD aged 8–15 years. Reading outcomes were analysed using Percentage of Non-overlapping Data (PND) and adjusted Tau-U effect size metrics. Findings Significant improvements in reading performance were obtained, yielding a combined PND of 88.9% and adjusted Tau-U of 0.64, indicating high effectiveness. Stronger effects were observed for phonemic awareness, while moderate effects in reading Fluency were likely influenced by participants’ cognitive and speech-related challenges. Conclusion Despite limitations such as a small sample size and OCR sensitivity to lighting conditions, the findings demonstrate the potential of low-cost TUI applications to enhance Swahili reading instruction for learners with IDLD in resource-scarce inclusive settings.