How do users really interact with their mobile devices : an activity analysis

In a previous part of the metro studies, we had a close look at how users interact with their mobile devices, by observing a large panel of users and taking snapshots of their activity.

To go further in the analysis, this article will dissect the way users interact with their mobile devices by analyzing timed interaction sequences on 110 users, in real life situations.

What this study is about and what it isn’t

  • This study takes in account interactions types and durations, switching from one interaction mode to another and task interruptions.
  • These results are not representative of total duration of interactions. The recordings were started when encountering users : it is impossible to know when they have started their activity. The recording stops when users put their mobile back in their pocket or move out of range. As a result, the total interaction time of a user with their device only reflects our observation strategies, and not user behaviour.
  • This study only deals with one specific context : users are on the move, in a train or in the underground. While these results are accurate for mobile interactions, they do not cover situations where users are at home or at the office for example.

Participants and data set description

We have observed a total of 110 participants and recorded a total of 6 hours and 23 minutes of activity. We focused on tracking the interactions of users, and did not record all context information for each of them. The following table presents for how many of the participants we have gathered each type of information

Number of participants for which we have the information about :
sex (male or female) 94
position (sitting or standing) 94
task (texting, reading or playing) 40
interaction (thumbs or index, one hand, two hands or cradle) 106

The participants split about 50-50 in terms of gender.

Women 56%
Men 44%


About two thirds of participants were sitting, one third was standing. We did not include walking users in this study, since recording their interactions would have required us to follow them, and that would have been too intrusive.

Sits 62%
Stands 38%


In terms of interaction, we did not want to be too intrusive either. As a result, we found acceptable to write down a general activity category such as reading, texting or playing. We only gathered this information if the screen was directly visible to us, but did no effort to find out if it wasn’t visible naturally.

Texting 48%
Texting and reading 3%
Reading 15%
Playing 35%


Device orientation

97.3% of users held their devices vertically, which is the same proportion we found in the previous studies.

In terms of time, this represents 18 minutes : 5% of the total recorded interaction times.


How long do users interact with their mobiles devices in a certain way ?

Users spend most time interacting with their devices with one thumb, whether their hold their device in one hand, or cradle it.


The proportions in which users are observed holding their devices are consistent in all three studies :


We observe fewer one handed usage because we observed fewer walking users.

In terms of time, these proportions vary slightly. Two handed use seems to be less frequent if you take in account the activity duration, however, globally, the results remain consistent.


What we did not learn from the previous study, is the proportions between interaction times and task interruptions. So based on our latest data, the most accurate representation of proportions in user interactions with their mobile devices is the following :


As you can see, about 7% of the time spent interacting with a mobile device on the move is actually not spent interacting with it. The other proportions similar, even taking this in account. More importantly, 14% of the time, users actually interact with their mobile using their index, and not their thumb.


With this study, we have shown 3 things, and are raising yet more questions :

  • When observing users through “snapshots” we got results that actually reflect the proportions of tracking time spent performing the activities we were interested in. The proportions we got didn’t just come from luck or from the method we used
  • Users actually use their thumbs to interact with their mobiles 70% of the time, and both their thumbs 9% of the time, when they are on the move, in the underground
  • Mobile users are actually idle 7% of the time that they are interacting with their devices

However, we still don’t know how they switch from one interaction mode to another, how they chain their interactions and what this being idle covers. These will be the aspects we will discuss in our next post on the metro studies. In the mean time, how would you use this knowledge to improve your mobile designs ?