Correlates of the cognitive dimensions for tangible user interface

We describe an application of the cognitive dimensions (CDs) of notations framework to tangible user interfaces (TUIs)—interaction with computers using physical devices other than mice and keyboards. We are particularly interested in situations where the TUI is used to construct some information structure (a manipulable solid diagram) and where that structure is intended to specify computer behaviour other than by direct manipulation (a tangible programming language). We analyse several tangible programming languages that have been described in previous research, considering the ways in which their physical properties influence the manipulability of the diagrammatic structure. This is the contribution that a CDs analysis would provide for any notation, but we find consistent ways in which particular dimensions can be predicted to apply to any solid diagram. We describe these as the tangible correlates of those dimensions. We then demonstrate that the tangible correlates can be used for both generative and analytic purposes in early stages of TUI design, much as CDs are applicable to the design of visual notations, but more immediately recognisable in their physical implications. r 2006 Elsevier Ltd. All rights reserved.