Improved Phone Call UI (CHI 2014)


Mobile phones have evolved from communication devices to multi-purpose computing devices. However, smartphones still use full-screen notifications for incoming calls, which interrupt whatever activity the user was already engaged in. We propose new designs that allow users to postpone calls and also to multiplex by way of a smaller partial-screen notification. We report on a small-scale controlled lab study as well as a large-scale study in-the-wild. Our contribution is an enhanced interaction design for handling incoming calls on smartphones.


Matthias Böhmer, Christian Lander, Sven Gehring, Duncan Brumby, Antonio Krüger: Interrupted by a Phone Call: Exploring Designs for Lowering the Impact of Call Notifications for Smartphone Users. In: Proceedings of CHI ’14, Toronto, ON, Canada.

Android App

We implemented the findings of our research and released an app for Android smartphones. You’ll find it on Google Play.

Study on Icon Arrangement (CHI 2013)




A Study on Icon Arrangement by Smartphone Users
Matthias Böhmer, Antonio Krüger
In: Proceedings of ACM SIGCHI Conference on Human Factors in Computing Systems. Paris 2013, France (to appear).



The number of available mobile applications is steadily increasing. People have rapidly adopted application stores as means to customize their devices with various functionalities that go beyond communication. Understanding the principles of mobile application usage is crucial for supporting users within this new ecosystem. In this paper, we investigate how people organize applications they have installed on their devices. We asked more than 130 participants for their habits for icon arrangement and collected more than 1,400 screenshots of their devices’ menus to further ground our findings. Based on this data we can distinguish five different concepts for arranging icons on smartphone menus, e.g. based on application usage frequency and applications’ functional relatedness. Additionally, we investigated how these concepts emerge in relation to frequency of application installations, removals and icon rearrangements, as well as users’ experience levels. Finally we discuss implications for the design of smartphone launchers, and highlight differences to icon arrangement on stationary computers.

Also see our studies on mobile app usage and mobile app multitasking, and our study on the impact of context on icon arrangement.


The data we used in this paper is available for you to draw your own conclusions. Please contact me if you need any additional pieces of information.

Screenshots of smartphone launcher menus