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A Tangible System for Learning Relational Algebra

Tangible User Interfaces (TUIs) are those in which users interact with a digital system through the direct manipulation of physical objects (tokens). Tokens are directly linked to a certain data/functionality within the system, so manipulation of these objects affects the system behavior. This paper introduces TanQuery, a tangible system to support the process of learning Relational Algebra. TanQuery incorporates components to detect and track tokens, and to analyze and execute query trees. The system was tested by university students, and obtained results allowed to observe and analyze that students found this type of interface useful and pleasant. 
Keywords: Tangible user interfaces; relational algebra.