Papers accepted at CHI 2018

Papers on Estimating Finger Orientation and Reducing Latency using Machine Learning

We will present two papers at the International Conference on Interactive Surfaces and Spaces. For both papers, we trained models that to improve the interaction with smartphones. PredicTouch is a system to reduce touchscreen latency using neural networks and inertial measurement units. With the second paper, we provide a ground truth data set for to estimate finger orientations using capacitive touchscreens recorded with a high-precision motion capture system. Using the data set, we show that a convolutional neural network can outperform approaches proposed in previous work.

Tutorial on Intelligent Mobile User Interfaces @ MobileHCI

Together with Sven and Huy, I’ll give a tutorial on Machine Learning for Intelligent Mobile User Interfaces using TensorFlow. One key feature of TensorFlow includes the possibility to compile the trained model to run efficiently on mobile phones. This enables a wide range of opportunities for researchers and developers. In the tutorial, we teach attendees two basic steps to run neural networks on a mobile phone: Firstly, we will teach how to develop neural network architectures and train them in TensorFlow. Secondly, we show the process to run the trained models on a mobile phone.

CHI 2016 Videos

The Effect of Focus Cues on Separation of Information Layers

Video for our CHI 2016 paper “The Effect of Focus Cues on Separation of Information Layers”, written by Patrick Bader, Niels Henze, Nora Broy and Katrin Wolf.

Impact of Video Summary Viewing on Episodic Memory Recall

Video for our CHI 2016 paper “Impact of Video Summary Viewing on Episodic Memory Recall”, written by Huy Viet Le, Sarah Clinch, Corina Sas, Tilman Dingler, Niels Henze, and Nigel Davies.

CHI 2015 Videos

Modeling Distant Pointing for Compensating Systematic Displacements

Video for our CHI 2015 paper “Modeling Distant Pointing for Compensating Systematic Displacements”, written by Sven Mayer, Katrin Wolf, Stefan Schneegass and Niels Henze.

Subjective and Objective Effects of Tablet’s Pixel Density

Video for our CHI 2015 paper “Subjective and Objective Effects of Tablet’s Pixel Density”, written by Lars Lischke, Sven Mayer, Katrin Wolf, Alireza Sahami Shirazi and Niels Henze.

Text Entry on Tiny QWERTY Soft Keyboards

Video for our CHI 2015 paper “Text Entry on Tiny QWERTY Soft Keyboards” written by Luis A. Leiva, Alireza Sahami, Alejandro Catala, Niels Henze and Albrecht Schmidt from the Universitat Politècnica de València and the University of Stuttgart.

Investigation of Material Properties for Thermal Imaging-Based Interaction

Video for our CHI 2015 paper “Investigation of Material Properties for Thermal Imaging-Based Interaction”, written by Yomna Abdelrahman, Alireza Sahami Shirazi, Niels Henze and Albrecht Schmidt.

CHI 2014 Videos

Large-Scale Assessment of Mobile Notifications

Our CHI video 2014 for our paper Large-Scale Assessment of Mobile Notifications, written by Alireza Sahami Shirazi, Niels Henze, Tilman Dingler, Martin Pielot, Dominik Weber, and Albrecht Schmidt.

Exploiting Thermal Reflection for Interactive Systems

Our CHI video 2014 for our paper Exploiting Thermal Reflection for Interactive Systems, written by Alireza Sahami Shirazi, Yomna Abdelrahman, Niels Henze, Stefan Schneegass, Mohammadreza Khalilbeigi and Albrecht Schmidt.

Delay Time for Pre-Moderated User-Generated Content on Public Displays

Our CHI video 2014 for our note I Can Wait a Minute: Uncovering the Optimal Delay Time for Pre-Moderated User-Generated Content on Public Displays, written by Miriam Greis, Florian Alt, Niels Henze and Nemanja Memarovic.

Why Android is so Awesome – for Prototypes and Research

Smartphones currently become the most pervasive computing devices of all times. They currently become even the best-selling consumer electronic devices of all. Obviously there is a huge amount of research that investigates how people use their phones and how we can improve their experience. If doing research using smartphones, an important practical question is which platform one should choose. Basically, there are three major platforms left and alive: iOS on the iPhone, Windows Phone, and Android.


Developing for Android is nice but developing for the other platforms isn’t worse. While Java might not be the most innovative language it easily beats iOS’s Objective C (garbage collection anyone?) and is almost on par with the .NET languages (and you could also use one of the other JVM languages). What makes Java compelling is the huge number of available examples but what really sticks out (for us) is that all our computer science students have to learn Java in the first semester. This means that every single, somewhat capable, student knows how to program Java that is even used throughout their university courses. It also comes in handy (actually this is already a real show stopper) that unlike developing for iOS you don’t need a Mac and unlike Windows Phone you don’t need Windows. Linux, Windows, MacOS – yes they can all be used to develop for Android (and those who like the pain can also use BSD).


Android is free and open. Sure, it is probably free like beer and not like free speech but you can still look into the code. Being able to look into your OS’s source code might seem like an academic detail… One of my former students had to look into the Android’s sources to understand the memory management for developing commercial apps. Having the source code enabled us to understand the Android keyboard and reuse it during our studies. We even patched Android to develop handheld Augmented Reality prototypes. All this is only possible if you have the source code available. For these examples, it might not be necessary to look in the code on other platform. Still, at one point or another you might want to dig down to the hardware level and you are screwed if it isn’t Android that you have to dig through.


While developing prototypes and conducting lab studies is nice at one point or another you might want to deploy your shiny research prototype. It might be for research, it might be for fun, or just for the money. Deploying your app in the Android market takes just seconds (if you already have those screenshots and descriptions readily available). There is no approval process. No two weeks waiting until Apple decides that your buggy prototype is – just a too buggy prototype. All you need is 25$ and a credit card (and a Google Account and a soul to sell).

Market share

Windows Phone will certainly increase its market share by some 100% soon – which isn’t difficult if you start from 0.5%. However, Android overturned all other platforms, including iOS and Blackberry. The biggest smartphone manufacturer is Samsung with their Android phones. They sell more smartphones than Nokia and they sell more smartphones than Apple. Well, and they are not the only company with an Android phone in their portfolio.


Fragmentation is horrible! I developed for Windows Mobile and for JavaME. Even simple applications need to be tested on different devices to hope that it works. Things aren’t too bad for Android (if you don’t use the camera or some sensors or recent APIs or some other unimportant things…). Fragmentation can even be great for the average mobile HCI researcher. Need a device with a big screen or with a small display? Fast processor, long battery life, TV out, or NFC? There is a device for that! There are very powerful and expensive devices (the ones you will use to test your awesome interface) but also very cheap ones for less than 80€ (that you can give to your nasty students).

Usability, UX, …

Android offers the best usability of all platforms ever – well probably not. Would I buy an Android phone for my mother? If money doesn’t count I would certainly prefer an iPhone. What would I recommend to my coolish step brother? Certainly a Windows Phone to impress the girls. But what would I recommend to my students? There is nothing but Android!