scott <sco### [at] scottcom> wrote:
> > But Windows progress bars do, in fact, go both forwards and backwards, 
> > seemingly at random. ;-)

> The best is when it gets to 99 or 100% and then *starts again* at 0% !

  There actually are some programmers out there (even pros) who have actually
not understood the idea of the progress bar. They seem to think it's something
akin go the spinning wheel which is often used when the total time is unknown
(ie. the spinning wheel simply indicates that something is being done, but
the program has no way of knowing how much will be done).

  Other programmers (sadly a lot of them) understand the purpose of the
progress bar, but they don't understand how it should be used so that it's
actually informative to the user. The most typical error is that if the
task done by the program consists of dozens of sub-tasks (such as eg.
installing a dozen of files), the progress bar is used to indicate the
progress of each individual subtask instead of using it to indicate the
overall progress. Thus the progress bar becomes useless (and more akin to
the spinning wheel).

  More competent programmers (or program designers) will put *two* progress
bars in the UI: One to indicate the progress of the sub-task and the other
to indicate overall progress. That's a whole lot more informative (although
the sub-task progress bar is not so useful if each sub-task is very fast to
perform, but more useful if they are slowish operations).

  Of course even then there's room for incompetence: For example, a progress
bar that updates too rarely and makes big jumps, or which pauses for too
long at the beginning or the end (nothing is more confusing than having
the overall progress bar at 100%, but the program still doing things for
several tens of seconds). Of course depending on the task in hand it may
be quite difficult programmatically to update the progress bar smoothly,
but still...

-- 
                                                          - Warp

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