An Evaluation of Input Controls for In-Car Interactions

The way drivers operate in-car systems is rapidly changing as traditional physical controls, such as buttons and dials, are being replaced by touchscreens and touch-sensing surfaces. This has the potential to increase driver distraction and error as controls may be harder to find and use. This paper presents an in-car, on the road driving study which examined three key types of input controls to investigate their effects: a physical dial, pressure-based input on a touch surface and touch input on a touchscreen. The physical dial and pressure-based input were also evaluated with and without haptic feedback. The study was conducted with users performing a list-based targeting task using the different controls while driving on public roads. Eye-gaze was recorded to measure distraction from the primary task of driving. The results showed that target accuracy was high across all input methods (greater than 94%). Pressure-based targeting was the slowest while directly tapping on the targets was the faster selection method. Pressure-based input also caused the largest number of glances towards to the touchscreen but the duration of each glance was shorter than directly touching the screen. Our study will enable designers to make more appropriate design choices for future in-car interactions

Investigation of dynamic three-dimensional tangible touchscreens: Usability and feasibility

The ability for touchscreen controls to move from two physical dimensions to three dimensions may soon be possible. Though solutions exist for enhanced tactile touchscreen interaction using vibrotactile devices, no definitive commercial solution yet exists for providing real, physical shape to the virtual buttons on a touchscreen display. Of the many next steps in interface technology, this paper concentrates on the path leading to tangible, dynamic, touchscreen surfaces. An experiment was performed that explores the usage differences between a flat surface touchscreen and one augmented with raised surface controls. The results were mixed. The combination of tactile-visual modalities had a negative effect on task completion time when visual attention was focused on a single task (single target task time increased by 8% and the serial target task time increased by 6%). On the other hand, the dual modality had a positive effect on error rate when visual attention was divided between two tasks (the serial target error rate decreased by 50%). In addition to the experiment, this study also investigated the feasibility of creating a dynamic, three dimensional, tangible touchscreen. A new interface solution may be possible by inverting the traditional touchscreen architecture and integrating emerging technologies such as organic light emitting diode (OLED) displays and electrorheological fluid based tactile pins

Tactile discrimination of material properties: application to virtual buttons for professional appliances

An experiment is described that tested the possibility to classify wooden, plastic, and metallic objects based on reproduced auditory and vibrotactile stimuli. The results show that recognition rates are considerably above chance level with either unimodal auditory or vibrotactile feedback. Supported by those findings, the possibility to render virtual buttons for professional appliances with different tactile properties was tested. To this end, a touchscreen device was provided with various types of vibrotactile feedback in response to the sensed pressing force and location of a finger. Different virtual buttons designs were tested by user panels who performed a subjective evaluation on perceived tactile properties and materials. In a first implementation, virtual buttons were designed reproducing the vibration recordings of real materials used in the classification experiment: mainly due to hardware limitations of our prototype and the consequent impossibility to render complex vibratory signals, this approach did not prove successful. A second implementation was then optimized for the device capabilities, moreover introducing surface compliance effects and button release cues: the new design led to generally high quality ratings, clear discrimination of different buttons and unambiguous material classification. The lesson learned was that various material and physical properties of virtual buttons can be successfully rendered by characteristic frequency and decay cues if correctly reproduced by the device

Crossmodal audio and tactile interaction with mobile touchscreens

Touchscreen mobile devices often use cut-down versions of desktop user interfaces placing high demands on the visual sense that may prove awkward in mobile settings. The research in this thesis addresses the problems encountered by situationally impaired mobile users by using crossmodal interaction to exploit the abundant similarities between the audio and tactile modalities. By making information available to both senses, users can receive the information in the most suitable way, without having to abandon their primary task to look at the device. This thesis begins with a literature review of related work followed by a definition of crossmodal icons. Two icons may be considered to be crossmodal if and only if they provide a common representation of data, which is accessible interchangeably via different modalities. Two experiments investigated possible parameters for use in crossmodal icons with results showing that rhythm, texture and spatial location are effective. A third experiment focused on learning multi-dimensional crossmodal icons and the extent to which this learning transfers between modalities. The results showed identification rates of 92% for three-dimensional audio crossmodal icons when trained in the tactile equivalents, and identification rates of 89% for tactile crossmodal icons when trained in the audio equivalent. Crossmodal icons were then incorporated into a mobile touchscreen QWERTY keyboard. Experiments showed that keyboards with audio or tactile feedback produce fewer errors and greater speeds of text entry compared to standard touchscreen keyboards. The next study examined how environmental variables affect user performance with the same keyboard. The data showed that each modality performs differently with varying levels of background noise or vibration and the exact levels at which these performance decreases occur were established. The final study involved a longitudinal evaluation of a touchscreen application, CrossTrainer, focusing on longitudinal effects on performance with audio and tactile feedback, the impact of context on performance and personal modality preference. The results show that crossmodal audio and tactile icons are a valid method of presenting information to situationally impaired mobile touchscreen users with recognitions rates of 100% over time. This thesis concludes with a set of guidelines on the design and application of crossmodal audio and tactile feedback to enable application and interface designers to employ such feedback in all systems

The Effect of Tactile and Audio Feedback in Handheld Mobile Text Entry

Effects of tactile and audio feedback are examined in the context of touchscreen and mobile use. Prior experimental research is graphically summarized by task type (handheld text entry, tabletop text entry, non-text input), tactile feedback type (active, passive), and significant findings, revealing a research gap evaluating passive tactile feedback in handheld text entry (a.k.a. texting ). A passive custom tactile overlay is evaluated in a new experiment wherein 24 participants perform a handheld text entry task on an iPhone under four tactile and audio feedback conditions with measures of text entry speed and accuracy. Results indicate audio feedback produces better performance, while the tactile overlay degrades performance, consistent with reviewed literature. Contrary to previous findings, the combined feedback condition did not produce improved performance. Findings are discussed in light of skill-based behavior and feed-forward control principles described by Gibson (1966) and Rasmussen (1983)

Interaction techniques for older adults using touchscreen devices : a literature review

International audienceSeveral studies investigated different interaction techniques and input devices for older adults using touchscreen. This literature review analyses the population involved, the kind of tasks that were executed, the apparatus, the input techniques, the provided feedback, the collected data and author's findings and their recommendations. As conclusion, this review shows that age-related changes, previous experience with technologies, characteristics of handheld devices and use situations need to be studied

Survey of Eye-Free Text Entry Techniques of Touch Screen Mobile Devices Designed for Visually Impaired Users

Now a days touch screen mobiles are becoming more popular amongst sighted as well visually impaired people due to its simple interface and efficient interaction techniques. Most of the touch screen devices designed for visually impaired users based on screen readers, haptic and different user interface (UI).In this paper we present a critical review of different keypad layouts designed for visually impaired users and their effect on text entry speed. And try to list out key issues to extend accessibility and text entry rate of touch screen devices.Keywords: Text entry rate, touch screen mobile devices, visually impaired users

An Evaluation of Touch and Pressure-Based Scrolling and Haptic Feedback for In-car Touchscreens

An in-car study was conducted to examine different input techniques for list-based scrolling tasks and the effectiveness of haptic feedback for in-car touchscreens. The use of physical switchgear on centre consoles is decreasing which allows designers to develop new ways to interact with in-car applications. However, these new methods need to be evaluated to ensure they are usable. Therefore, three input techniques were tested: direct scrolling, pressure-based scrolling and scrolling using onscreen buttons on a touchscreen. The results showed that direct scrolling was less accurate than using onscreen buttons and pressure input, but took almost half the time when compared to the onscreen buttons and was almost three times quicker than pressure input. Vibrotactile feedback did not improve input performance but was preferred by the users. Understanding the speed vs. accuracy trade-off between these input techniques will allow better decisions when designing safer in-car interfaces for scrolling applications