"Most software packages employ progress bars to visualize the status of an ongoing process. Users rely on progress bars to verify that an operation is proceeding successfully and to estimate its completion time. Typically, a linear function is applied such that the advancement of a progress bar is directly proportional to the amount of work that has been completed. However, estimating progress can be difficult for complex or multi-stage processes. Varying disk, memory, processor, bandwidth and other factors complicate this further. Consequently, progress bars often exhibit non-linear behaviors, such as acceleration, deceleration, and pauses. Furthermore, humans do not perceive the passage of time in a linear way. This, coupled with the irregular behavior of progress bars, produces a highly variable perception of how long it takes progress bars to complete. An understanding of which behaviors perceptually shorten or lengthen process duration can be used to engineer a progress bar that appears faster, even though the actual duration remains unchanged. This paper describes an experiment that sought to identify patterns in user perception of progress bar behavior."
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Member since:2005-07-06
You beat me to it. The biggest, and most annoying, example of this is the Windows MSI installer. It progress bar is no reflection at all on how the install is progressing, and it insists on going back to the beginning several times. The net effect of this is that a user simply doesn't believe it at all, and finds it annoying that it seems to be deliberately trying to mislead.
I don't believe this is the correct article, because the link I'm getting is to do with Vista SP1.
Member since:2005-07-06
This commment is coming in:
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I agree. People should not use a 0-100% progress bar for unknown quantities. They should only be used when the exact number of items/events is known. When I am in an unknown situation that may take a while, I usually show the user a status bar displaying items or events as they are processed. Then they know what is happening, and can see progress (items changing), but they are given no false illusion of percentage of progress.
[Edited for spelling]
Edited 2008-03-05 22:24 UTC
Member since:2005-07-08
Here's the correct link: http://chrisharrison.net/projects/progressbars/
And there's a short summary of the study at least here too:
http://kostuff.blogspot.com/2008/01/progress-bars-to-make-people-ha...
To quote the last article:
"Chris Harrison et al. has a paper showing that people perceive time as running faster if they are looking at an appropriately accelerating progress bar. It seems that a progress bar that slows in the beginning and accelerates near the end (called "Fast Power" in the paper) makes people happiest."
Edited 2008-03-05 22:46 UTC
Member since:2005-07-06
Member since:2007-09-06
The best setup I've seen used is a two bar combination for current step and total progress. The current process bar can restart over and over as long as the total progress bar ticks along slowly with an accurate estimate of remaining time.
Someone could even do it as a pair of circles with total progress wrapped around process if they wanted to be different.
I agree fully on a single progress bar that starts over for each process step though; it's usless screen clutter that does nothing but tease the user.
Member since:
2005-12-15
This is all very nice, but probably the single best thing developers could do is not employ the exceptionally annoying concept of once the progress bar reaches 100% it then goes back to 0% and starts all over again, and then repeats this 50 times..
It would be better to just have some spinning icon like in Firefox or IE which symbolises it's still working, rather than give people false hope that it's almost complete.