Robert studied Computer Engineering at Technische Universität Berlin and received his diploma degree in 2011. Beginning 2008, Robert has worked with the Usability- and the Mobile and Physical Interaction group of Telekom Innovation Laboratories as a student assistant. In 2011 he continued his activities as research assistant and is now working towards his PhD.
His research interests are focused on full-body interaction with large interactive public displays, concentrating on immediate comprehension and usability.
The project with Nina Valkanova allows for a great and novel way of urban participation: passers-by get the opportunity to place a vote on local topics by performing body gestures in front of a large public display installation.
Deployment at SUPERMARKT towards Wedding's sidewalks.
Setting up the system
We investigate how to reveal an initial mid-air gesture on interactive public displays. This initial gesture can serve as gesture registration for advanced operations. We propose three strategies to reveal the initial gesture: spatial division, temporal division, and integration. Spatial division permanently shows the gesture on a dedicated screen area. Temporal division interrupts the application to reveal the gesture. Integration embeds gesture hints directly in the application.
The system was deployed for one week in a public university building. During the installation we captured 558 individual user session for later analysis.
This image perfectly illustrates why we baptized our novel gesture Teapot.
To refine our techniques and to preselect a set of conditions to be tested in a field study, we invited 166 participants to a preliminary lab study. Each participant was exposed to one gesture visualization. Based on if and when participants executed the presented gesture, we measured the effectiveness of each technique.
Recorded depth-videos and screen captures were the basis of our analysis.
The framework for the study was a small game: users had to feed a giant monster by tossing cubes in its mouth. After successfully performing the gesture, they got a bunny mask! :-)
The system was also installed for 3.5 months in a Telekom Shop at Kurfürstendamm in Berlin, one of Germany's most visited shopping avenues. We used Telekom-branded assets in order to comply with the corporate design.
We propose a novel initial gesture called Teapot to illustrate our strategies. Our main findings from a laboratory and field study are: A large percentage of all users execute the gesture, especially with spatial division (56%). Users intuitively discover a gesture vocabulary by exploring variations of the Teapot gesture by themselves, as well as by imitating and extending other users’ variations.
In this project with Jörg Müller we investigated how passers-by notice the interactivity of public displays. We designed an interactive installation that uses visual feedback to the incidental movements of passers-by to communicate its interactivity.
The lab study reveals: (1) Mirrored user silhouettes and images are more effective than avatar-like representations. (2) It takes time to notice the interactivity (approx. 1.2s).
In the field study, three displays were installed during three weeks in shop windows, and data about 807 persons interacting were collected. Our observations show: (1) Significantly more passers-by interact when immediately showing the mirrored user image (+90%) or silhouette (+47%) compared to a traditional attract sequence with call-to-action. (2) Passers-by often notice interactivity late and have to walk back to interact (the landing effect). (3) If somebody is already interacting, others begin interaction behind the ones already interacting, forming multiple rows. Our findings can be used to design public display applications and shop windows that more effectively communicate interactivity to passers-by.
Distant displays such as interactive public displays or interactive television require new interaction techniques as traditional input devices may be limited or missing in these contexts. Free hand interaction, as sensed with computer vision techniques, presents a promising interaction technique. In this project with Gilles Bailly we present the adaptation of three menu techniques for free hand interaction: Linear menu, Marking menu and FingerCount menu.
Users could use their left hand to select a category and their right hand to select an item from that category. In total they could pick one out of 25 items simply by showing a number of fingers to the screen.
We propose a simple algorithm to detect and track the user's fingertips based on depth images from the kinect. You can see the algorithm in this video.
The first study based on a Wizard-of-OZ protocol focuses on Finger-Counting postures in front of interactive television and public displays. It reveals that participants do choose the most efficient gestures neither before nor after the experiment. Results are used to develop a Finger-Count recognizer. The second experiment shows that all techniques achieve satisfactory accuracy. It also shows that Finger-Count requires more mental demand than other techniques.
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Robert Walter, Gilles Bailly, Jörg Müller. (2013) StrikeAPose: Revealing Mid-Air Gestures on Public Displays. to appear. (CHI '13) |
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Jörg Müller, Robert Walter, Gilles Bailly, Michael Nischt, Florian Alt, (2012) Looking glass: a field study on noticing interactivity of a shop window. In Proceedings of the SIGCHI Conference on Human Factors in Computing Systems. (CHI '12) |
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Maurice Ten Koppel, Gilles Bailly, Jörg Müller, Robert Walter, (2012) Chained displays: configurations of public displays can be used to influence actor-, audience-, and passer-by behavior. In Proceedings of the SIGCHI Conference on Human Factors in Computing Systems. (CHI '12) |
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Gilles Bailly, Robert Walter, Jörg Müller, Tongyan Ning, Eric Lecolinet, (2011) Comparing free hand menu techniques for distant displays using linear, marking and finger-count menus. In Proceedings of the 13th IFIP TC 13 international conference on Human-computer interaction - Volume Part II. (INTERACT'11) |
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Tongyan Ning, Jörg Müller, Robert Walter, Gilles Bailly, Chat Wacharamanotham, Florian Alt, Jan Borchers, (2011) No Need to Stop: Menu Techniques for Passing by Public Displays. In CHI 2011 Workshop on Large Displays in Urban Life: from Exhibition Halls to Media Facades. (CHI '11)
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Since 2011, I supervise the exercises and the projects of the Mobile Interaction module of Quality and Usability Lab of TU Berlin. In the exercise, students learn the basics of the famous creative coding environment Processing and get introduced to the Kinect Camera and the OpenNI framework.
Using these tools, students practically apply the interaction design process taught in the lecture and create small projects in groups. The task is to create an intuitive yet engaging interactive public display application.
Within 7 weeks, students go from brainstorming ideas and defining personas of the target audience, over storyboard, conducting interviews with potential users, paper prototyping, to the first iteration of a software prototype. The prototype is then redefined using methods of heuristic evaluation and a think-aloud user study. Students document the progress of their work in a project blog (check the links below).
In that semester we had great 15 projects (70 students) working on the topic of Interactive Waiting Area Experience. Note that the projects displayed here is not my work but the result of student projects of our HCI course! Visit the corresponding blogs to get more information.
You play a drunkard: shift your body and try not to tumble!
A Southpark-themed racing game that you control by bending your body. You can also throw snow balls!
A FruitNinja-like game that you can play with your body.
In that semester we had 12 projects (57 students). Note that the projects presented here is not my work, but results of our student projects. Check out a list of noticeable projects below!
Players have to place specific body parts on predefined, moving targets on a circle around their body.
How about an air guitar that you can actually play? Air BEnd allows you to play virtual instruments together.
Make Graffiti, Not Vandalism - Touchless Interaction with Public Display using KINECT
Displaid is a dating platform presented as an public interactive display.