Radial Menus, Release to Select

Engaget recently covered the release of a new mobile device by Enblaze. I like the radial interface, and the move away from buttons, which in my opinion is one of the weakest interactions of a touch screen. Some downsides of this approach include

• accidental triggering of features when you lose your grip momentarily
• Bias or inefficiency (unless it automatically switches) to switch between left and right hands
• Loss of spatial memory
• Loss of the visual efficiency in vertical and horizontal grid alignment

Comments

[Josh]

Not only is there a problem with accidental triggering, but because accessing menus is done in one continuous step by opening multiple submenus, it requires much more concentration; if you make a mistake it will take you much longer to recover, and it makes it harder to be doing anything else. I would also argue that although you can get to things with "one click" which is ostensibly faster than multiple clicks, it would actually take you longer to get to most items this way.

[Keith Lang]

Thanks Josh — yeah, I agree that dragging around while maintaining contact can be a difficult thing — I noticed my GF struggling to drag an icon to the dock with her trackpad. She found it difficult because the distance required 'clutching' with the trackpad.

[Adrian]

The Littlesnappr iPhone app by Rapidweaver has a radial menu wheel that I thought was quite ingenious. It's less flashy than this example, but works really quite well.

[Jamie]

I wonder if you could elaborate on why you think that buttons are one of the weakest interactions of a touch screen. Isn't tapping or touching a graphical representation of a physical object the simplist and therefore most obviously identifiable interaction one can have with a touchscreen?

One issue with the divice showen above in my mind is that the 'drag' action is right to left which is somewhat counter-intuitive to most ltr reading people. The LittleSnapper app wheel mentioned above is positioned on the left edge of the screen and definitly 'feels' better, however that wheel functions more like a scrolling list than a real radial interface.

[Keith Lang]

Hi Jamie

"f you could elaborate on why you think that buttons are one of the weakest interactions of a touch screen"

Yes - touching the 'actual button' is a great interaction on a touch screen. However, the interaction of tapping itself suffers because:
- Unlike a real button, your finger doesn't get the sensation of making contact with the button before you commit to a button-press
- The actual detected point of contact differs from the intention of the user — Steve Jobs talked about this in the iPhone intro. You can test this out if you get access to an iPhone and go to the Notes.app. Turn the phone on it's side, but carefully make sure the app doesn't auto rotate. Try with the keyboard sideways, you'll note it's sometimes the key below that gets 'pressed' when you intended the key above — the iPhone is no longer compensating in the correct manner.
- There is a lot of smarts in touch screen that guess what a 'tap' is, and also what a 'finger down' is.

All these things add up to a lot of guesswork by the computer, and also the human at the exact point of touch — unlike dragging which can give continuous feedback to let the human know that the computer understands what they want.

I'm confident these problems will be overcome as touchscreens improve, with haptics, and optical 'mouseOver' like abilities.

I completely agree with your 'drag right to left' action. Perhaps it goes the other way in the other hand.

[Marc Nothrop]

I'd love to be proven wrong, but I suspect this UI could get a little annoying, but that may just be lack of familiarity, let alone not having actually used the thing!

I absolutely agree with all of the issues raised here, and while it's been alluded to, I reckon ergonomics deserve to be high on the list.

...it's basically been alluded to ("clutching the phone"), but my main concern would be the length of drag operations, and the physical tension required to maintain contact with the screen while dragging (surface resistance?), to track/follow UI elements, and then release at the right time.

As you've indicated Keith, this sort of radial approach will have to overcome the existing 'problems' with Pie menus (familiarity, spatial integrity/predictability, and a degree of modality in making each selection.)

I also wonder about the granularity of commands executed via this 'global' UI mechanism, vs individual app mechanisms… at some point there will have to be some level of direct manipulation; some commands will have to be collocated with the object they act upon (e.g. the 'T' arrangement and appended "Call" buttons shown in the Contacts app.)

Finally while this is a bit anecdotal, without the force-feedback of a physical control people can tend to press too hard on a touch screen, which can lead to fatigue, or even joint pain, so a UI built upon extended screen contact could be problematic… anyone experienced 'iPhone thumb' yet?! :)

Great to see different approaches though, and it will be interesting to play with this UI.