design mobile interaction

Fingers and Thumbs

Mobile devices have transformed the way we deal with computer technology. We now have amazingly powerful computers that fit into the palms of our hands making it possible to have them with us at all times and be able to do many of the tasks we used to only be able to do on computers and more.  

The miniturization of this technology has given us amazingly high quality displays and the integration of multiple capabilities such as cameras, GPS, accelerometers, and the like. However, getting information into these tiny devices, while improving, still has a ways to go. Even though speech technologies are improving, most people still use software keyboards. The use of software keyboards isn't uniform either though with some people using their thumbs, others using their fingers, and yet others preferring the swipe type keyboard alternatives. As usual, I thought I would ask my social media networks what they do. I asked "Do you use your thumb(s), finger(s), or voice when entering information into you Smartphone?" The results are shown to the right. Voice input was predictably low at 8 percent and alternative keyboard input technologies that involve swiping across the keys yielded an even smaller number (but then I didn't specifically list this as an alternative).  The majority of respondents indicated that they use their thumbs but, surprising to me and to others on Twitter who commented on this, fingers were preferred by fully 34 percent of respondents. Of note as well is that 2 percent of those who use thumbs actually only use one thumb and 4 percent of those who use fingers, just use one.

I rarely use Siri now and use both thumbs when entering information into my iPhone.  I thought that most people were roughly the same and was surprised to see people using their fingers. However, these results indicate that I was wrong and I suspect that others may be surprised by these results too. 

What implications does this have for designers of mobile apps? First, absolutely minimize the information that a user has to enter into your app given that it is still a suboptimal input mechanism. And second, don't assume that users are using their thumbs. The designers of Flipboard (an app that I love and many, many others do too) decided to adopt an entirely new interaction pattern when they moved their app from the iPad to the iPhone with the former optimized for fingers and the latter optimized for thumbs. These results call into question the assumption that Smartphone users use their thumbs. Of course the majority of Smartphone users use their thumbs, according to my unscientific study, but a sizable percentage of users actually use their fingers.

Lastly, we smug thumb Smartphone users should stop snickering at the occasional friend or family member who uses their fingers on their Smartphone and realize that there are more of them than we initially realized.