Our software has dialogs for sending requests to other users. Dialogs remain open as long as default until the request has been answered (request time about 3 to 15 seconds). During this response time i want to show a progress indicator as visual feedback.
Should i use a standard progress indicator or an individual icon animation?
I think a standard progress indicator will be used usually only for system processes.
Example for a standard progress indicator:
There is no should here. You need an in progress indicator here, but as long as the people using your site recognise that it's an in progress indicator the exact nature of it isn't that important besides choosing something that looks good.
The one that you've given in your question is a very common one and is usually a good choice.
I was looking into this issue recently. I think what you're looking for is more of an Activity indicator than a progress indicator. Different indicators are used for different lengths of time. Progress indicators have more of a definitive start / end (such as the typical Microsoft 0-100% one) however it sounds like you only need to show that the application is currently busy for a short period of time, not what it's busy doing and how long it's going to take to complete.
An interesting article about different usage of progress/activity indicators is over at MSDN - Progress Bars
Think about how the user will interpret your progress indicator.
If by standard progress indicator, you mean changing the cursor to a spinner or hourglass then I'd save that for system related tasks or where the application is effectively blocked from any further interaction (at any level).
The problem with using the cursor for this is that often this is seen more as a problem than as progress. The longer the cursor spins, the less confident the user is that it's going to come back.
Additionally, using the cursor does not contextualize the wait. Effectively you are saying the whole application is blocked.
In contrast, if you put an animated spinner right next to the message in your dialog, then you are contextualizing the wait in terms of the specific task going on in that dialog, and that is less worrying for the the user.
I would always try and locate the busy animation right where the update or next bit of information is going to appear - even if it's just a success message.
If by individual icon animation you mean an animation for example with two computers and symbols flying backwards and forwards between the two, or an animated signal moving along a network cable, or rings animated round the earth, then you don't need that kind of animation, so yes, save that for operating systems - it's too overkill inside an application dialog.
Just keep it simple - use the animated spinner. It's familiar, and does the job neatly and succinctly. It does not need to have any added value (baggage) by being an animation of information flowing about as this starts to delocalize the wait away from the context. The user doesn't care about information flying between computers - they care about the dialog and the response. By adding an animated internet/network, people will blame the internet for being slow, which leads to 'bigger picture frustration'.
By the way - I think perhaps 'Busy' is a better term than 'Progress' in this scenario.
When I order pizza online, after payment it sends the order to my pizza place of choice and displays a page with a progress indicator while the restaurant responds. This takes around a minute generally.
If the progress indicator was a basic spinner, I feel I'd blame the site or network for being slow. But instead they have this simple but effective graphic with an iconic pizza hut with a satellite dish receiving information waves.
This tells me rather effectively that what I'm actually waiting for is someone at that hut to acknowledge my order (which is done manually) - without actually involving network or internet icons.
So yes, I agree - it could make a difference. The context and placement of the spinner however would likely have more importance than whether it's graphically distinct from system waits or not.
My suggestion from a purely artistic standpoint would be a (small) animated icon of a peer (person/silhouette/face), a standard mail icon and an animated directional arrow or trail showing a message is in transit to a peer. This should be possible to make very small and unobtrusive while still be clear, and of course it needs to be properly contextually located.
