The author has developed a diagrammatic representation of use cases for TI-Nspire, mapping from numeric, syntactic or geometric problems onto calculator functions: numeric-measured, numeric-calculated, numeric - tabulated, syntactic, graphical-coordinate points, graphical-function graph, geometric.
This is a book chapter:
Clark-Wilson, A. (2012). Integrating multi-representational software into mathematics teaching -- trajectories of teachers' practices. Visual Mathematics and Cyberlearning. D. Martinovic and V. Freiman. The Netherlands, Springer. 1: 300.
The book is scheduled for publication in summer 2012.