Who hasn't experienced that because their thumb is quite generous in size, they had to experience moments of high tension because the blessed button on the screen did not work correctly or because it was a button smaller than a mustard seed. There UI design - also known as User Interface - has a lot to say and facilitate.

Everything that has to do with the UI within mobile usability contains notes of creativity, adaptability and optimization. Those who dedicate their daily lives to studying the modes of interaction between users and screens are aware that when outlining a mobile archetype, not only purely technical arguments are valid, but also the reasons that encompass the person who is going to use it.

We are talking about that for the UI designer, in addition to caring about the interface to be used, his main attention must be focused on the analysis of the uses and customs of the recipients of the app or website. That is, knowing how to detect the context in which they are used, the type of device used, the frequency of use, the age group of the user and so on. People must have in their possession a device that allows them to see a screen that contains valuable information and strategically arranged.

In general, all people tend to use their cell phones at different times and circumstances, whether standing on the bus, doing physical activity, standing in line at the supermarket or staying inside a car. 

UI usability today

In devices used today, almost the entire front surface is a screen and users need to be able to see it in its entirety.

As a result of concerns about how people interact with their phones, mobile interface design expert Steven Hoober conducted a social study to determine behavioral patterns. Thus, over two months, around 1,300 observations were made of individuals using these devices while on public roads, in airports, bus stops, cafes and trains. From this, it was found that of the total sample, 780 people were touching the screen to scroll or type, touch or use other gestures to enter data. The rest only listened, watched or spoke through their mobile devices.

The question of hands

In more than 40% of the observations made, a user interacted with a mobile phone without entering any data through a key or screen. In this, 22% of the sample spent their time making voice calls, while 19% carried out passive activities such as listening to audiovisual content.

It was also possible to detect that the users did not maintain a static form of support but rather that it varied as the seconds passed. Within the analysis it can also be highlighted that on repeated occasions, people exchanged hands to obtain extra reach, using both hands to write text messages, and then returning to the initial position of a single hand and so on.

As for the ways of holding the devices, three large groups were distinguished: with one hand -represented by 49%-, cradled -represented by 36%- and finally, with two hands -represented by 15%-. 

Those who use only one hand to access the functionalities of a smartphone, it was discovered that 49% of this group holds the device in multiple ways. In this way, 67% of those observed showed greater use of their right thumb on the screen and 33% reflected that they used their left finger to do the same.

One-handed use seemed to be highly correlated with simultaneous performance of other tasks for Hoober. Many of those who used one hand to hold their phone were performing other tasks such as carrying bags, steadying themselves when in transit, climbing stairs, opening doors, carrying babies, etc.

Cradling is the term used for those who use two hands when holding a mobile phone, but only use one hand to touch the screen or buttons. According to studies carried out, 36% of people who cradle their mobile phone use it in two different ways: with their thumb or finger. Holding a phone with two hands provides more support than one-handed use and allows users to freely interact with their phone using their thumb or finger. Likewise, it was detected that 72% used their thumb on the screen and the vast majority did so from their left hand.

Traditionally we associate two-handed use with writing on QWERTY boards. Two-handed use was prevalent among 15% of mobile phone users. In two-handed use, users hold their device with their fingers and use both thumbs to provide input, as they would on a desktop keyboard. An interesting fact to note was that 90% of people held the phone vertically in portrait mode. While only 10% did it in a landscape, horizontally.

Also notable was the use of devices in their portrait orientation or portrait mode, despite theories about the ease of typing with a larger keyboard area. However, a large percentage of sliding keyboards force horizontal use. 

Conclusions

Having analyzed these advances, the UI expert assures that his inclination for testing user interface designs became much stronger as a result of this research. Whether you've created a working prototype, screenshots, or just a paper prototype to scale, it's essential to test it on a mobile device or an object with similar dimensions and hold it in all the ways users would. 

You will likely hold it to ensure that your fingers do not obscure relevant content from the user so that the buttons they would need to touch are not difficult to reach.