Anna Ostberg

User Experience Researcher

Gesture Input on a Fingerprint Sensor
An exploratory study of gestural input on a fingerprint sensor that used card sorting and Wizard-of-Oz demos to investigate people’s perceptions of this new input method.
The goal of this work was to develop new useful applications for a smartphone fingerprint sensor. I generated interaction ideas, implemented a Wizard-of-Oz demo, ran sessions of think alouds & card sorting, and analyzed results. The goal was to use the highly sensitive touch data from the fingerprint sensor to enable useful smartphone interactions. This takes advantage of the fingerprint sensor’s ergonomic location by using gestures to expand its usefulness beyond simply unlocking the device.
The research sessions consisted of semi-structured interviews with ten participants, each lasting about 30 minutes. Initially I interviewed people about their general smartphone use and interactions. This was followed by a card sorting exercise and think aloud, which dove into the specific proposed gestures and interactions. This was accompanied by a Wizard-of-Oz demo that I implemented because a working demo was not available at the time. I built demos in HTML and controlled them using a Bluetooth keyboard to communicate with the smartphone. When the participants had assigned a gesture to an interaction, this allowed them to try it out in a realistic fashion. Finally, participants provided ratings and verbal comments for each gesture.
General reactions to the proposed concepts were positive and the study revealed a few gestures that were viewed favorably by most participants, as well as possible actions to initiate using those gestures. Results were presented and shared with other researchers, engineering, and product marketing teams. About a year after this work was completed and shared, several phones entered the market with features exactly like those explored in this research. The results were also published as late-breaking work at the CHI conference in 2016, and received a Best Paper Honorable Mention award.
Example of a participant’s final card sort, showing mappings between gestures and interactions.
Participants' average ratings for the six proposed gestures. Ultimately double tap and swipe left/right were the most preferred gestures.