The computer is the only machine in history to be able to reverse time. Other machines can mow, shred, hoe, plant, reap, mold, lathe, copy, stitch, glue. But none can Undo. And Undo is a transformative distinction.
Undo allows you to start over again. To remove regrets. To feel and retain the pains and joys from a discarded future and to do it differently, hopefully better, again. Editors, spreadsheets, simulations; their power lies in the Undo.
Undo affords you a new human experience. It moves the intellectual exercise of “what-if” into the gut-feeling of “should-have”. Undo lets you be a continuously enriched component of the process, providing critical management and business intelligence the computer can not yet attain.
Undo has much to offer data visualization. You are still better at seeing visual patterns than the computer is, but there is still much to be done in this field in terms of time-sequence loops and Undo.
A studied use of Undo will raise user interface design into the more compelling stratum of user experience design.