Martin Pielot

Tactile wayfinder: a non-visual support system for wayfinding

Digital maps and route descriptions on a PDA have become very popular for navigation, not the least with the advent of the iPhone and its Google Maps application. A visual support for wayfinding, however, is not reasonable or even possible all the time. A pedestrian must pay attention to traffic on the street, a hiker should concentrate on the narrow trail, and a blind person relies on other modalities to find her way. To overcome these limitations, we developed a non-visual support for wayfinding that guides and keeps a mobile user en route by a tactile display. We designed a belt with vibrators that indicates directions and deviations from the path in an accurate and unobtrusive way. Our first user evaluation showed that on an open field without any landmarks the participants stayed well to given test routes and that wayfinding support is possible with our Tactile Wayfinder.

An in-situ study of mobile phone notifications

Notifications on mobile phones alert users about new messages, emails, social network updates, and other events. However, little is understood about the nature and effect of such notifications on the daily lives of mobile users. We report from a one-week, in-situ study involving 15 mobile phones users, where we collected real-world notifications through a smartphone logging application alongside subjective perceptions of those notifications through an online diary. We found that our participants had to deal with 63.5 notifications on average per day, mostly from messengers and email. Whether the phone is in silent mode or not, notifications were typically viewed within minutes. Social pressure in personal communication was amongst the main reasons given. While an increasing number of notifications was associated with an increase in negative emotions, receiving more messages and social network updates also made our participants feel more connected with others. Our findings imply that avoiding interruptions from notifications may be viable for professional communication, while in personal communication, approaches should focus on managing expectations.

Didn't you see my message?: predicting attentiveness to mobile instant messages

Mobile instant messaging (e.g., via SMS or WhatsApp) often goes along with an expectation of high attentiveness, i.e., that the receiver will notice and read the message within a few minutes. Hence, existing instant messaging services for mobile phones share indicators of availability, such as the last time the user has been online. However, in this paper we not only provide evidence that these cues create social pressure, but that they are also weak predictors of attentiveness. As remedy, we propose to share a machine-computed prediction of whether the user will view a message within the next few minutes or not. For two weeks, we collected behavioral data from 24 users of mobile instant messaging services. By the means of machine-learning techniques, we identified that simple features extracted from the phone, such as the users interaction with the notification center, the screen activity, the proximity sensor, and the ringer mode, are strong predictors of how quickly the user will attend to the messages. With seven automatically selected features our model predicts whether a phone user will view a message within a few minutes with 70.6% accuracy and a precision for fast attendance of 81.2%

TouchOver map: audio-tactile exploration of interactive maps

This article reports on a preliminary study, which investigates if vibration and speech feedback can be used in order to make a digital map on a touch screen device more accessible. We test if vibration feedback combined with speech, triggered as the finger moves over relevant map objects, works to make sense of the map content. The study results indicate that it is indeed possible to get a basic overview of the map layout even if a person does not have access to the visual presentation. In the conclusions the interaction problems are indentified and suggestions for future improvements are given.

My App is an Experiment: Experience from User Studies in Mobile App Stores

Experiments are a cornerstone of HCI research. Mobile distribution channels such as Apples App Store and Googles Android Market have created the opportunity to bring experiments to the end user. Hardly any experience exists on how to conduct such experiments successfully. This article reports on five experiments that were conducted by publishing Apps in the Android Market. The Apps are freely available and have been installed more than 30,000 times. The outcomes of the experiments range from failure to valuable insights. Based on these outcomes, the authors identified factors that account for the success of experiments using mobile application stores. When generalizing findings it must be considered that smartphone users are a non-representative sample of the worlds population. Most participants can be obtained by informing users about the study when the App had been started for the first time. Because Apps are often used for a short time only, data should be collected as early as possible. To collect valuable qualitative feedback other channels than user comments and email have to be used. Finally, the interpretation of collected data has to consider unpredicted usage patterns to provide valid conclusions.

Supporting map-based wayfinding with tactile cues

Paper maps are a proven means for navigating in unfamiliar environments, however, they do not prevent people from getting lost or taking unwanted detours. A well-known issue is interpreting the maps geocentric content, which is known to become prone to errors when the map is not aligned to the environment. In this paper we report our investigation of providing a cue about the destinations location from an egocentric perspective in order to improve the interpretation of the map. We used a vibrotactile belt to continuously indicate a destinations direction relative to the users orientation. In an outdoor field study we compared the performance of map-based navigation with and without the added tactile cue. We found evidence that people take shorter routes, consult the map less often, and were less often disoriented with the tactile cue. Furthermore, females found the tactile cue more useful and used it more often.

PocketNavigator: studying tactile navigation systems in-situ

In this paper, we report about a large-scale in-situ study of tactile feedback for pedestrian navigation systems. Recent advances in smartphone technology have enabled a number of interaction techniques for smartphone that use tactile feedback to deliver navigation information. The aim is to enable eyes-free usage and avoid distracting the user from the environment. Field studies where participants had to fulfill given navigation tasks, have found these techniques to be efficient and beneficial in terms of distraction. But it is not yet clear whether these findings will replicate in in-situ usage. We, therefore, developed a Google Maps-like navigation application that incorporates interaction techniques proposed in previous work. The application was published for free on the Android Market and so people were able to use it as a navigation system in their everyday life. The data collected through anonymous monitoring suggests that tactile feedback is successfully adopted in one third of all trips and has positive effects on the users level of distraction.

Size matters (spacing not): 18 points for a dyslexic-friendly Wikipedia

In 2012, Wikipedia was the sixth-most visited website on the Internet. Being one of the main repositories of knowledge, students from all over the world consult it. But, around 10% of these students have dyslexia, which impairs their access to text-based websites. How could Wikipedia be presented to be more readable for this target group? In an experiment with 28 participants with dyslexia, we compare reading speed, comprehension, and subjective readability for the font sizes 10, 12, 14, 18, 22, and 26 points, and line spacings 0.8, 1.0, 1.4, and 1.8. The results show that font size has a significant effect on the readability and the understandability of the text, while line spacing does not. On the basis of our results, we recommend using 18-point font size when designing web text for readers with dyslexia. Our results significantly differ from previous recommendations, presumably, because this is the first work to cover a wide range of values and to study them in the context of an actual website.

PocketMenu: non-visual menus for touch screen devices

We present PocketMenu, a menu optimized for non-visual, in-pocket interaction with menus on handheld devices with touch screens. By laying out menu items along the border of the touch screen its tactile features guide the interaction. Additional vibro-tactile feedback and speech allows identifying the individual menu items non-visually. In an experiment, we compared PocketMenu with iPhones VoiceOver. Participants had to control an MP3 player while walking down a road with the device in the pocket. The results provide evidence that in the above context the PocketMenu outperforms VoiceOver in terms of completion time, selection errors, usability. Hence, it enables usage of touch screen apps in mobile contexts (e.g. walking, hiking, or skiing) and limited interaction spaces (e.g. device resting in a pocket).

Tacticycle: supporting exploratory bicycle trips

Going on excursions to explore unfamiliar environments by bike is a popular activity in many places in this world. To investigate the nature of exploratory bicycle trips, we studied tourists on their excursions on a famous vacation island. We found that existing navigation systems are either not helpful or discourage exploration. We therefore propose Tacticycle, a conceptual prototype of a user interface for a bicycle navigation system. Relying on a minimal set of navigation cues, it helps staying oriented while supporting spontaneous navigation and exploration at the same time. In cooperation with a bike rental, we rented the Tacticycle prototype to tourists who took it on their actual excursions. The results show that they always felt oriented and encouraged to playfully explore the island, providing a rich, yet relaxed travel experience. On the basis of these findings, we argue that exploratory trips can be very well supported by providing minimal navigation cues only.