Many were surprised when Apple’s iPhone 4S was released with the same size screen as the past several years. In a crowded market when mobile screens are getting larger and larger, some now barely fitting into a pocket, so why would Apple stick with the same size display? Those who have studied mobile phone use know, but it’s worth exploring how ease of use really depends on how you work the phone with your thumb.
Android phones in particular have copied most of the interface and features of the iPhone in the past years, but where does one go to innovate? Obviously, more camera megapixels is one path. A faster processor is another. But little has the wow factor of a larger screen. The problem is you hit up again usability if the screen gets too large.
Most users hold and interact with their phones in the same way; it is held in one hand, and selection is typically used with the thumb. Sitting down for a session of games or videos or surfing is a different matter; two hands are often the norm. But for quick pulling it out of your purse or pocket and checking something, one hand and one thumb can do it. The iPhone 4S screen size ensures that your thumb can reach the entire screen — meaning you can hold the unit in one hand and reach everywhere quickly, with one finger and one hand. Larger screens? Not so easy. When a screen gets over a certain size, your thumb cannot make it to the opposite side, and you must move the other hand on to it.
When you think about it, it does not seem like a big deal. But in actual use, it matters quite a bit. Two hands demand much more attention, and motor skill fatigue can easily ramp up. If you think of the phone as a mini tablet for sitting and enjoying video and text content, it is not too much of a concern. But for an on-the-go mobile data center used in a busy day, one thumb can be much more productive.
While the iPhone 4S has remained tightly focused on design and usability, and it looks like the screen will remain the same for the near future, other mobile phones show no sign of slowing the screen real-estate expansion. A quick scan of any phone dealer will show that mobile screens are getting larger and larger, with no signs of easing up. While bigger may be better, it’s worth exploring how usability is impacted, as bigger may require more fingers and hands to really get the most out of.
