I'm working on a usability study of an interface that shows a globe. You're currently able to click, hold, and drag the globe to move it around (i.e. view the other side of Earth). In testing, I've found users can do this intuitively just fine.

You're also able to zoom in, but to do so, you need to "Ctrl + left click and drag, or right click and drag." Users utterly failed at figuring out how to do this in testing, even when presented with written instructions on the screen. (It's also terribly trackpad unfriendly.)

So, my question is, has there been any research into the best practices or the best keyboard/mouse combos for how to zoom? My initial guess would be to model it off of Google Maps (and allow for double clicking, using the scrolly wheel, and having visible +/- buttons), since a good number of people are familiar with that app, but I'd prefer to point to something more academically based.

Also, note that this is not a web app; it's standalone downloadable software.

  • 2
    Visible zoom in/out buttons are mandatory, since no set of zoom actions is easily discoverable.
    – dbkk
    Mar 9, 2012 at 6:39
  • @dbkk - Although, one could argue that, for multi-touch at least, pinch-in/pinch-out is quickly becoming standard / expected behavior.
    – cdeszaq
    Mar 9, 2012 at 14:05
  • 1
    @cdeszaq yeah, pinch to zoom is quite predictable, as long as you're not expecting touchpad people to use it. It makes perfect sense on a phone.
    – Ben Brocka
    Mar 9, 2012 at 14:15
  • @BenBrocka - Ahh, true. I don't often use a touchpad that is disconnected from the actual screen. I forgot about the issues that disconnect causes.
    – cdeszaq
    Mar 9, 2012 at 14:17

3 Answers 3


Though I would like to go with what elumalai suggested i.e using Cntrl (+) and Cntrl (-) (or command (+) or command (-) in Mac's) to zoom in and zoom out respectively ,the challenge you would face with that approach is that these are system defined shortcuts and unless you can find a way of overriding them,you will not be able to use these. Hence I would go with your suggested approach of how Google maps does it since thats something which conforms to users mental models of zooming into maps.

However if you do want to use the feature of key board shortcuts,ensure those shortcuts are are always docked in the side somewhere the user can glance to see how they are done.

Since users are testing your application for the first time,they would be hard pressed to remember those shortcuts but if you have a visual aid which tells them what keyboard shortcuts are associated with what action,you will help them in learning it faster and becoming better power users.

Lastly,I am not a fan of you using the keyboard and mouse at the same time to zoom in,The reason is that it requires me to be aware of what both my hands are doing and limits my ability to just one one hand.

Try experimenting with shortcuts like Shift+ A (for zooming in) and shift + (z) for zooming out to see how the users adapt to that and choose the one which shows the greatest return and ease of learning.

Here are some zoom options I found

enter image description here

enter image description here

  • I wouldn't use Ctrl+A or Ctrl+Z for something else than "mark all" and "undo". What about PageUp/PageDown Keys?
    – FrankL
    Mar 9, 2012 at 8:28
  • My apologies,I forgot that Cntrl+z and cntrl+a are predefined shortcuts,I just updated my answer. The problem with up and down keys is they are generally used for scrolling up and scrolling down and using them as zoom is confusing
    – Mervin
    Mar 9, 2012 at 8:34

I think in your case I wouldn't invent a new zooming process, just simply use what Google Earth does! (which is also a desktop app)

On the other hand what extra features does your product include what Google Earth doesn't have?

  • 2
    +1 (but more info on what Google Earth does do): So essentially, Google Earth is an interactive publication of the results of the research that Google did themselves into this area - ie have a visible Zoom slider with clickable buttons for immediate interaction by anyone. Thumbwheel and double click (left=in, right=out) as discoverable back up for the more savvy, further appended by click & drag up/down. I'm good with that idea. See also Youtube video of navigation in Google Earth. Mar 9, 2012 at 10:34
  • Thanks for reminding me about Google Earth... forgot about that, haha. And thanks @Roger for the zooming rundown. I'm not familiar with Google Earth's UI, so that was quite helpful. Thanks for the help including everyone else that's replied! Mar 9, 2012 at 18:09

Downloadable software also has (Ctr +/-) option for Zoom In Zoom Out like Adobe Collections.

IMHO is (Ctrl +) Zoom In (Ctrl -) for Zoom Out. We need to stick with with what users are originally comfortable with.

Also we need to consider for basic shortcut keys. Then only you need to change the natural things.

My second opinion is:

We can use (ctrl + >) Zoom In (Ctrl + <) for Zoom Out.

  • Is this just your personal opinion, or do you have any research supporting this suggestion? The OP has asked specifically for research or evidence.
    – JonW
    Mar 9, 2012 at 7:07

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.