freehand drawing interfaces explored in 60s (light pens ) but failed, the mouse won
now tablets+ pda offer drawing tools: renewed interest towrds freehand drawing interfaces
especially used in design, architecture,a bit for military operations
support creative design but not so many work in coordination or field activities

general thoughts about sketching: V. Goel, Sketches of Thought, MIT Press, Cambridge MA, 1995. Robbins, E. (1994). Why Architects Draw. Cambridge, MA: MIT Press. Tversky, B. (2002). What do Sketches say about Thinking? AAAI Spring Symposium

historical dimension: I. Sutherland. Sketchpad - a Graphical Man-Machine Interface [Ph.D. Dissertation]. M.I.T., 1963.

sketching and groupware: Greenberg, S., Hayne, S., & Rada, R. (1995). Groupware for Real-Time Drawing. London: McGraw Hill.

systems used in a design context: 1996 Gross, M. D. "The Electronic Cocktail Napkin - computer support for working with diagrams," Design Studies. 17(1), 53-70.

1996 Gross, M.D. and E. Do. "Ambiguous Intentions: A paper-like interface for creative design", Proceedings ACM Conference on User Interface Software Technology (UIST) '96 Seattle, WA. 183-192 Landay, J. A., & Myers, B. A. (1995). "Interactive Sketching for the Early Stages of Interface Design, CHI '95 - Human Factors in Computing Systems", (pp. 43-50). Denver, Colorado: ACM Press.

system used by the US army Forbus, K., Usher, J., and Chapman, V. (2003). Sketching for military courses of action diagrams. In York, A. P. N., editor, Proceedings of the 8th international conference on Intelligent user interfaces, pages 61–68, Miami, Florida.