Toni Pakkanen

Methods for Presenting Braille Characters on a Mobile Device with a Touchscreen and Tactile Feedback

Three novel interaction methods were designed for reading six-dot Braille characters from the touchscreen of a mobile device. A prototype device with a piezoelectric actuator embedded under the touchscreen was used to create tactile feedback. The three interaction methods, scan, sweep, and rhythm, enabled users to read Braille characters one at a time either by exploring the characters dot by dot or by sensing a rhythmic pattern presented on the screen. The methods were tested with five blind Braille readers as a proof of concept. The results of the first experiment showed that all three methods can be used to convey information as the participants could accurately (91-97 percent) recognize individual characters. In the second experiment the presentation rate of the most efficient and preferred method, the rhythm, was varied. A mean recognition accuracy of 70 percent was found when the speed of presenting a single character was nearly doubled from the first experiment. The results showed that temporal tactile feedback and Braille coding can be used to transmit single-character information while further studies are still needed to evaluate the presentation of serial information, i.e., multiple Braille characters.

Appropriateness of foot interaction for non-accurate spatial tasks

This paper describes alternative methods for manipulating graphical user interfaces with a foot. Feet are used in many real world tasks together with the rest of the body, but in computer environments they are almost completely put aside as an interaction possibility. One of the major problems in choosing input methods for different tasks in user interfaces is determining what kind of method is appropriate for a certain task. Feet could easily be used as a supportive input method in interaction with computers together with the traditional mouse. In this paper, we discuss the possibility of using foot input in different non-accurate spatial tasks, and the efficiency and usability experience the users have of foot interaction compared with a traditional hand-based interface with the same input device. The aim is to find out how well foot interaction suits for non-accurate spatial tasks.

Mobile devices as infotainment user interfaces in the car: contextual study and design implications

The spreading of mobile devices to all areas of everyday life impacts many contexts of use, including cars. Even though driving itself has remained relatively unchanged, there are now a wide variety of new in-car tasks, which people perform with both integrated infotainment systems and their mobile devices. To gain insights into this new task context and how it could be improved, we conducted a qualitative, contextual study in which we observed real-life car journeys with eight participants. The focus was on user interaction with touchscreen mobile devices, due to their wide range of functions and services. The findings show that the car is an extension of other contexts and it contains a rich set of infotainment tasks, including use of social media. Drivers emphasized gesture interaction and the use of non-visual modalities, for replacing visual information and notifying of changes in the driving context. Based on the findings, we present design implications for future in-car infotainment systems.

Comparison of three designs for haptic button edges on touchscreens

Systematic research on haptic stimuli is needed to create suitable haptic feeling for user interface elements. In this study we compared three alternative designs for creating haptic edges for buttons. All the designs compared are based on the physical parameters of graphical user interfaces and thus they are applicable for different kinds of user interfaces. A handheld prototype device with haptic feedback created by piezoelectric actuators integrated in the touch screen was used in the experiment. The designs used were minimalistic (Simple), direct transformation of visual pixels to haptic pixels (GUI transformation) and iterative design (Designed). The amplitude, the number of haptic bursts (haptic pixels) and the delay between the bursts was varied in this experiment. The results showed that the most promising designs were Simple and Designed. Less haptic bursts and less delay between the bursts were preferred by the users. The preferred level of the amplitude varied and thus should be adjustable.

Perception of low-amplitude haptic stimuli when biking

Haptic stimulation in motion has been studied only little earlier. To provide guidance for designing haptic interfaces for mobile use we carried out an initial experiment using C-2 actuators. 16 participants attended in the experiment to find out whether there is a difference in perceiving low-amplitude vibrotactile stimuli when exposed to minimal and moderate physical exertion. A stationary bike was used to control the exertion. Four body locations (wrist, leg, chest and back), two stimulus durations (1000 ms and 2000 ms) and two motion conditions with the stationary bicycle (still and moderate pedaling) were applied. It was found that cycling had significant effect on both the perception accuracy and the reaction times with selected stimuli. Stimulus amplitudes used in this experiment can be used to help haptic design for mobile users.

Comparison of extensive vs. confirmation haptic interfaces with two levels of disruptive tasks

In the car environment there are more and more complex infotainment systems, which are used with touchscreens, even by driver while driving the car. While it is known that secondary tasks have a negative impact to the driving safety, there is a lack of information, if haptics can be used to make this interaction safer. In this study we compared two haptically enhanced user interfaces with two levels of user distraction: Commonly used confirmation haptic interface, and extensive haptic interface, where all possible information was provided with haptics. In the experiment participants entered four-digit numbers, while driving or watching video. Input speed, input error rate, driving errors and subjective experiences were recorded. The results showed that there were no significant performance differences between the user interfaces, but the extensive haptic interface helped to reduce the number of driving errors. Participants did not have significant preference differences between the user interfaces.

Haptic numbers: three haptic representation models for numbers on a touch screen phone

Systematic research on haptic stimuli is needed to create viable haptic feeling for user interface elements. There has been a lot of research with haptic user interface prototypes, but much less with haptic stimulus design. In this study we compared three haptic representation models with two representation rates for the numbers used in the phone number keypad layout. Haptic representations for the numbers were derived from Arabic and Roman numbers, and from the Location of the number button in the layout grid. Using a Nokia 5800 Express Music phone participants entered phone numbers blindly in the phone. The speed, error rate, and subjective experiences were recorded. The results showed that the model had no effect to the measured performance, but subjective experiences were affected. The Arabic numbers with slower speed were preferred most. Thus, subjectively the performance was rated as better, even though objective measures showed no differences.

Interaction with WebVR 360° video player: Comparing three interaction paradigms

Immersive 360° video needs new ways of interaction. We compared three different interaction methods to find out which one of them is the most applicable for controlling 360° video playback. The compared methods were: remote control, pointing with head orientation, and hand gestures. A WebVR-based 360° video player was built for the experiment.

Perception strategies in modal-redistributed interaction

Computer interfaces provide information to users mostly graphically. This method of presentation is not suitable for the visually impaired or for users in situations where interaction is limited, like in mobile context. One possibility to present information to these kinds of users would be using melodic sounds and haptic feedback to replace graphical information. We describe a new method to redistribute graphical information to melodic sounds and haptic cues with a stick interface. We discuss the impact of this redistribution to user behavior in simple shape recognition tasks. Appropriateness of redistribution is evaluated and design recommendations given based on user behavior in modal-redistributed interaction.

Audio-Haptic Car Navigation Interface with Rhythmic Tactons

While car environment is often noisy and driving requires visual attention, still navigation instructions are given with audio and visual feedbacks. By using rhythmic tactons together with audio, navigation task could be supported better in the driving context. In this paper we describe haptic-audio interface with simple two-actuator setup on the wheel using rhythmic tactons for supporting navigation in the car environment. The users who tested the interface with a driving game would choose audio-haptic interface over audio only interface for a real navigation task.