Alan Dix - research topics

Undo and History

I've studied aspects of undo off and on since I fist started working in HCI. Work over the years has included generic proofs using the PIE model, formal and conceptual work on multi-user undo (with Gregory Abowd) and use of dynamic pointers as a conceptual and implementation framework.

Recently collaborative work with Roberta Mancini and Stefano Levialdi has revisited single-user undo producing a formal framework that is both more rigorous than previous work and also applicable to other types of system extension, including hypertext history.

Undo is particularly well suited to formal analysis, although the analysis also reveals issues that must be dealt with outside the formal domain. In particular, there are psychological issues about the perceived granularity of undo. Also, the formal analysis of multi-user undo confirmed that some nasty cases will always remain. This lead to a radical rethink of the meaning of the "undo" button and the suggestion that design ought to focus on supporting the user's own undo actions.

There are also links between this work and an on-going study of versioning issues and dynamic pointers

Some of my papers

Roberta's thesis

Other undo papers

maintained by Alan Dix