Android Research

Will they use it? Will it be useful? In-Situ Evaluation of a Tactile Car Finder.

When we develop new technology, we want to know if it will have the potential to be successful in the real world.

This is not trivial! People may sincerely enjoy our technology when we expose them to it in a lab- or a field study. They may perform better than with previous solutions at the tasks that we ask them to fulfill as part of the study.

However, once they leave our lab they never again encounter the need to use it in their daily routines. Or, the utility we prove in our studies may not be evident in the contexts where this technology is actually deployed.

In our work, we made use of Google Play to answer these questions in a novel way. We wanted to study if a haptic feedback can make people less distracted from the environment, when they use their phone for pedestrian navigation in daily life. We developed a car finder application for Android phones with a simple haptic interface: whenever the user points into the direction of the car, the phone vibrates.

The data provides evidence that about half of the users use the vibration feedback. When vibration feedback is enabled, users turn off the display and stow away the device more often. They also look less at the display. Hence, when using vibration feedback, users are less distracted.

Our work shows that app distribution channels, such as Google Play or the iOS Store, can serve as a cheap way of bringing a user study into the daily life of people instead of bringing people into the lab. Compared to the results of a lab study, these findings have high external validity, i.e. we can be sure that our findings can be generalized to a large number of users and usage situations.

This work will be presented at NordiCHI ’12: The 7th Nordic Conference on Human-Computer Interaction, which takes place in Copenhagen in October 2012. The paper is available here (pdf).

Thanks to for summarising this work so nicely in their article Buzzing app helps smartphone dudes locate their car.

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Android Projects Research

A Tactile Compass for Eyes-free Pedestrian Navigation

The idea came up when I was heading back to the hotel from a conference dinner at MobileHCI 2008 in Amsterdam. I had no orientation. The only guide I had was a map on my Nokia phone. Not being familiar with Amsterdam, the route let me right through the busy areas of the city center.

The day before, a cyclist had stolen a mobile phone right out of the hand of another conference attendee. Knowing that made me quite afraid something similar could happen to me too. Without the phone I would have been completely lost.

Here, serendipity hit. Since my research group was already working on tactile displays for navigation and orientation, I wondered whether it was possible to create a navigation system for mobile phones that guided by vibration only, so it could be left in the pocket.

Back at OFFIS we quickly tested a few prototypes, including a hot/cold metaphor and a compass metaphor. The compass metaphor prevailed. The design was to encode the direction the user should be heading (forward, left, right, backwards) in different vibration patterns. Our testing participants liked that design most. Later we tested the vibration compass design a forest and found that it can replace navigation with a map.

The development and the studies was presented at the 13th IFIP TCI3 Conference in Human-Computer Interaction (INTERACT) in Lisbon, Portugal in September 2011. The article is available here.

If you own an Android phone you can try this vibration compass by downloading our PocketNavigator navigation application for free from the Android market.


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Digital Helpers for the Blind

Last year, the WDR (German TV broadcaster) together our HaptiMap project partner GeoMobile tested the the PocketNavigator with Mr. Schmidt who is visually impaired.

Actually, the PocketNavigator was not designed for blind users, since it only gives very coarse directions (straight, left, right, behind) via vibration patterns. However, to my surprise, Mr. Schmidt seemed to be able to get along with it quite well. He navigated by the white cane as usual but took the directions as orientation cues.

Screenshot of the PocketNavigators main map view

The test also showed that the PocketNavigator is not yet ready to be used by visually impaired users. During the test Mr. Schmidt accidentally hit the touch screen and changed the travel destination, which caused him ending up in front of a house.

Altogether, he was quite fond of the general principle. He concludes that the system would not be an “extra workload” when being on the move.

The video is available here: Digitale Helfer für Blinde, 15.10.2010 (German only)

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Turn-by-Turn Navigation – the Best Way to Guide Pedestrians?

Navigating from a place to another is an essential ability for a self-determined life. When navigating in unknown terrain, e.g. when going for a hike or when visiting a city as a tourist, people become increasingly dependent on navigation aids. Established aids range from signposts over maps to route descriptions. But, thanks to the increasing number of GPS-enabled mobile phones, a new navigation aid is becoming increasingly common: the GPS navigation system.

In principle, these systems behave like car navigation systems. The traveller’s location is displayed on a map, the route is highlighted, and turning instructions are given by symbols or speech. For cars, this way of guiding the driver has shown to be quite successful. Timely and accurate instructions are indispensable as the driver has to follow the traffic rules. For pedestrians, however, this type of information presentation may be too strict. Even worse, when providing too much navigation information, we neglect the human’s inherent navigation abilities and cause even disadvantages. For example, many people report that when driving a route by navigation systems, they cannot remember the route as well as they could before the area of car navigation systems.

Now just imagine a place that is roughly 1 mile away from your current location. If somebody would give you the rough cardinal direction of this place on demand, most people would reach it easily. We tested this kind of navigation in research group and currently offer it in the PocketNavigator. First, the user specifies the destination by selecting it on a map. The handheld then creates vibration patterns that indicate whether the destination is ahead, to the left-hand side, or to the right-hand side.

First studies show that pedestrians can effectively and efficiently navigate with such as directional cue only. Thus, showing the direction of a destination “as the crow flies” could be a valuable additional to turn-by-turn navigation systems for pedestrians.

For more information see  “In Fifty Metres Turn Left”: Why Turn-by-turn Instructions Fail Pedestrians

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Projects Research

Vibration-enhanced Paper Map Navigation

Maps are one of the oldest known information artifacts. An even in the times of GPS navigation systems, people still use them to find their ways in unknown environments.

One of the challenges when navigating by a map is that the map’s abstract content has to be matched to the traveler’s environment. It has for example been found that maps are easier to use when they are rotated so they align with the environment. We were interested if that matching would become easier if the user always knew were the destination was.

In our research we therefore coupled a GPS-enabled handheld with a vibro-tactile belt. The belt consists of eight vibration motors that equally distribute around the user’s waist. A built-in compass allows understanding in which direction the user is facing. The belt was then use to constantly vibrate into the direction of the traveler’s destination.

Traveler with a map and our vibro-tactile belt. The belt vibrates     into the direction of the traveler's destination.
Concept: convey the general direction of the destination with a vibro-tactile belt


In a field experiment with 16 participants we tested our approach in the wild. The participants had to reach two destinations, one with a paper map only and the other with the additional support of the vibro-tactile belt.

We found that the vibrational cues made participants less on the map, lose their orientation less often, and take shorter routes.

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