Is it OK for scrolling interactions to not scroll content?

Question

This is a general question about scrolling behavior with a trackpad or mouse. I've been discussing this with my peers, and it's become quite a debate.

Our conversations are specifically about the Google Maps website. When your mouse cursor is over the map area, scrolling with your mouse zooms rather than pans the map. When the Google Maps API is used to embed a map on your own website, scrolling down the page can steal the mouse cursor and zoom the map out in an instant.

Another example I can think of is QuickTime Player. Scrolling your mouse wheel while in an active window (say, a movie) will rewind or fast-forward the movie.

So my question is, is this kind of functionality good or bad? Does it help or damage what the the act of "scrolling" means?

Answer 1

In general my opinion is to not break the current pattern unless necessary. Consistency is always key. Therefore I think that if you're overriding the default scroll behavior of just panning up and down that there should be some serious thought behind it and usability testing to back it up. My thoughts would be if you're panning content in some direction when the user scrolls, then you're probably close enough where the user won't be incredibly confused and put-off. In general most people will assume it does what it usually does and that it will simply pan the screen vertically when you scroll.

However, I believe the cases you mentioned deserve a bit of the spotlight as well. As far as 3D navigation goes, I would say the Google Maps' override of the default scroll behavior is fairly standard as far as 3D navigation goes. I'm not sure if it's becoming a standard because of Google Maps, but it's definitely becoming commonplace. I do agree it is odd to have two differing patterns of scrolling in the same context (a single web page) though. Breaking consistency is more confusing than anything, which is why this is such a dangerous road to travel down.

As for the QuickTime example, I feel that is staying fairly true to the underlying concept of panning content, although when you think about it, it does feel odd. I believe there are more common interaction patterns for achieving fast forward and rewind a computer, but the granularity of control you get from a scrolling control is much better.

What it boils all down to is whether or not your target audience will find it intuitive enough to discover without effort, have it behave as expected with limited learning required, and that you have a consistent behavior across your application.

Answer 2

I find most map implementations where this is included inherently bad, and (having worked with Google Maps for five years or so) generally I regret that Google Maps introduced it.

The problem is not so much that the mousewheel controls zoom, but that it can get in the way. If you scroll down a page in such a way that a map turns up under the cursor, not only does scrolling break but you zoom the map out so it's ultra-small and useless.

On the main Google Maps site, the map occupies a substantial part of the screen and doesn't scroll with the page. So scroll-to-zoom is fine and actually intuitive. Where a map is simply positioned in a scrollable page, it's not a good idea to include scroll-to-zoom.

The same criticism may well apply to the QuickTime player, but I wasn't aware it did that (so presumably it's not so much of a problem because I've never scrolled media content instead of the page).

Answer 3

I would agree with GotDibbs. Intuitively the scroll action is implying we will get new content from the scroll direction, zoom in , zoom out.

If we are break this convention, you would really need to be careful, are you ready to create the new paradigm for the scroll action ?

for the google map example: I would say it is acceptable, although I think pan is also acceptable.

for the player example: I clearly remember I never used that interaction.