Techniques for augmented-tangibles on mobile devices for early childhood learning

Integrating physical learning materials with mobile device applications may have benefits for early childhood learning. We present three techniques for creating a hybrid tangible-augmented reality (T-AR) enabling technology platform. This platform enables researchers to develop applications that use readily available physical learning materials, such as letters, numbers, symbols or shapes. The techniques are visual marker-based; computer-vision and machine-learning; and capacitive touches. We describe details of implementation and demonstrate these techniques through a use case of a reading tablet app that uses wooden/plastic letters for input and augmented output. Our comparative analysis revealed that the machine-learning technique most flexibly sensed different physical letter sets but had variable accuracy impacted by lighting and tracking lag at this time. Lastly, we demonstrate how this enabling technology can be generalized to a variety of early learning apps through a second use case with physical numbers.