Moving Between Contexts
Any action is performed in a particular context. So what does it mean to do the ‘same’ thing in a different context? There is no simple answer to this question, it depends on the interpretation of the operation and even then may be ambiguous. This is not a purely theoretical problem, but occurs in practical computational problems. This paper examines this issue looking at three different problems: multi-user undo, distributed update and the simultaneous development of a document in multiple formats. In each case, we find formal rules which any sensible translation must obey. We also see that dynamic pointers, a generic specification and implementation concept defined in previous work, can be used to generate default translation rules which suffice in many circumstances. This is because dynamic pointers can themselves be seen as a translation of location information between different contexts.
KeywordsDefault Rule Dynamic Pointer Translation Rule Ascii Text Implementation Concept
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- 2.A. J. Dix. Dynamic pointers and threads. Collaborative Computing (accepted for publication), 1994.Google Scholar
- 3.A.J. Dix. Formal Methods for Interactive Systems. Academic Press, 1991.Google Scholar
- 4.Alan J. Dix and Victoria C. Miles. Version control for asynchronous group work. Technical Report YCS 181, Computer Science Dept., University of York, U.K., 1992. (Poster presentation HCI’92: People and Computers VII).Google Scholar
- 6.M.D. Harrison and A.J. Dix. Modelling the relationship between state and display in interactive systems. In P.Gornay and M.J.Tauber, editors, Visualisation in Human—Computer Interaction, volume LNCS 439, pages 241-249. Springer-Verlag, 1990.Google Scholar
- 8.Atul Prakash and Michael J. Knister. Undoing actions in collaborative work. In CSCWU92 — Proceedings of the Conference on Computer-Supported Cooperative Work, pages 273-280. ACM Press, 1992.Google Scholar
- 9.A. Schill. Cooperative Office Systems. Prentice Hall, 1995.Google Scholar
- 10.E Wright, A. Monk, and M. Harrison. State, display an undo: a study of consistency in display base interaction. Technical report, University of York, 1992.Google Scholar