Re: [Usability] What happened to Undo?

[Roberto Rosselli Del Turco <rosselli ling unipi it>]

Gregory Merchan wrote:
> Describing what Undo affects as a "micro-change" gives me cause to worry.
> Do we not have a better description of what Undo and Redo should do?
> The HIG has scattered references to Undo, but it never defines an undoable
> action. Indeed, we seem to be missing an entire section on user interaction
> where the definition would naturally fit. I don't know off-hand what else
> would be in that section, but a precise description of Undo seems a class
> apart from the existing sections.
>
> I think we should have Undo and maybe Defaults, but not Revert.

Actually we *have* Revert in at least one case: when editing panel icons 
properties (I wanted to point this out some time ago, but just forgot 
about it :)

> As I recall, we shouldn't have any unstable setting states. I'm at a loss
> to think of how they might occur. We have three basic types of settings:
> numerics, booleans, and strings. (GConf has a finer division, but that's
> not important here.) Because numerics should be bounded, an independent
> numeric should never cause instability. A fortiori, independent booleans
> shouldn't. When types depend on each other, stability is at risk. However,
> that risk should be mitigated using inconsistent or insensitive widget
> states. String types may be unavoidably dangerous when they have no natural
> boundaries. (A color value stored as a string is naturally bounded and the
> graphical interface can constrain input to those bounds.) I have trouble
> imagining a state that cannot be stabilized before irrevocable harm is done.
> Although a filename or a hostname is almost free-form, character restrictions
> not being very limiting compared to numerics, these are still bound by
> accessibility. That a named file does not exist or is not readable can be
> detected and the user notified. The only danger I can imagine is from a
> configuration that invokes a script.
>
> All of that is to say that the danger from Undo leaving settings in an
> unstable state is almost non-existent.
>
>
> Both Defaults and Revert can change many settings at once. These may number
> beyond what the user can recall. It would be disheartening to have changed
> many settings and then eliminated those changes by accidentally pressing
> Defaults or Revert. Given either, Undo is not just desirable, it is necessary.
> Because pressing Revert is the same as pressing Undo many times, it would
> be almost redundant; a click saver, nothing more. If we are to have either
> Revert or Defaults, we should have Defaults as it provides a unique function.
>
> And I believe we should have Defaults for more reasons than its trivial
> implementation. As someone working on GNOME, I want it to check defaults.
> As a help desk worker, I would want it as a bail-out measure. As a naive
> user, I might think that the developers know their stuff and have chosen
> good defaults. As an office worker who is sick and tired of not finding
> my own tweaks on every coworker's desk, I might chose to be less frustrated
> when they ask me for help.

I fully agree with you on all of the above.

Ciao

--
Roberto Rosselli Del Turco      e-mail:	rosselli at cisi.unito.it
Dipartimento di Scienze			rosselli at ling.unipi.it
del Linguaggio			Then spoke the thunder	DA
Universita' di Torino		Datta: what have we given?  (TSE)

  Hige sceal the heardra,     heorte the cenre,
  mod sceal the mare,       the ure maegen litlath.  (Maldon 312-3)