Emotionally overheated social media discussions cause many harms both to the individuals participating in the discussion and to the wider society. To support emotion regulation in social media discussions, the strategy of affect labelling is explored. Two experiments were run to study the effects of emotion labels presented with social media messages on participants’ emotional responses to the messages. Altogether 84 participants read emotional social media messages presented without and with emotion labels (Experiment 1, N = 39), and without labels and with emotion / control labels (Experiment 2, N = 45) and rated their subjective emotional valence. Results show that the ratings of valence were significantly higher for the positive messages presented with label than for the messages presented as such without emotion label or presented with a control label. In addition, the results of the second experiment show that the negative social media messages were experienced as more negative when the messages were presented with an emotion label than without emotion label or with control label. The results suggest that affect labelling of social media messages is an ineffective strategy to down-regulate emotions but could be used to support and strengthen positive emotions.

Uncivil commenting on online news articles tends to harm journalists, news readers, and public discourse. Recent HCI research proposes that such behaviour could be mitigated by alerts (e.g. instructional pop-up notifications) to users while writing seemingly impolite messages. However, the design space of such alerts and the contextual factors influencing users’ perceptions of them remain largely unexplored. Informed by principles of behaviour design, we examined the impact of three factors on the perceived quality and expected effectiveness of alerts: the level of politeness of the comment that the alerted user was responding to and the form and amount of guidance in alert designs. We used a 2 × 2 × 3 factorial quasi-experiment, implemented as an international online survey (N = 248) targeting online news commenters. The results showed that the politeness of the recipient impacted how the comment was perceived but had no effect on the evaluation of the alert. Additionally, alerts with behavioural guidance were preferred over those without. As for effects of background variables, participants’ commenting frequency was not found to influence alert scoring. This study expands our understanding of the design space for user interface alerts and the contextual factors that influence their perceived quality.

While HCI literature offers general frameworks for understanding user-centred quality, specific application areas may call for more detailed contextualisation of it. This paper focuses on socio-technical context of online news commenting by investigating speculative UI interventions intended to influence users’ emotions and social behaviour. To understand the aspects of quality that matter to users in such UI interventions, we conducted an international online survey (N = 439) and qualitatively analysed respondents’ first impressions of eight different design proposals. The findings describe contextually relevant socio-technical viewpoints and offer actionable considerations for design. For example, the findings imply that designers should be mindful of possible unintentional misuse that may result from the UI reinforcing specific emotional states or affording stigmatisation of individual users. The study advances understanding of which aspects of quality should be considered when designing and deploying UI interventions for digital media services and evaluating them with potential end-users.

Abstract An online experiment investigated the perceived effects of a user interface (UI) intervention aiming to support online news commenters' emotion regulation. By describing the comment's tone to the user, the expected effect was activation of the implicit emotion regulation process of affect labeling (i.e. naming emotions). The perceived emotion- and behavior-related effects of the labeling intervention were investigated using the experimental vignette methodology. Participants read a vignette describing the behavior of an uncivil commenter and assessed the commenter's probable responses to the labeling intervention or a control intervention shown in the UI. The results showed that, when compared to a control condition, the labeling intervention was assessed to evoke positive emotions and to result in mitigation of uncivil behavior. This suggests that UI solutions that support emotion regulation are a promising approach to reducing uncivil comments that users might afterward regret, and hence potentially improving the quality of online discussions.

On digital media services, uncivil commenting is a persistent issue causing negative emotional reactions. One enabler for such problematic behavior is the user interface, conditioning, and structuring text-based communication online. However, the specific roles and influences of UIs are little understood, which calls for critical analysis of the current UI solutions as well as speculative exploration of alternative designs. This paper reports a research-through-design study on the problematic phenomenon regarding uncivil and inconsiderate commenting on online news, envisioning unconventional solutions with a critical voice. We unpack this problem area and outline critical perspectives to possible solutions by describing and analyzing four designs that propose to support emotion regulation by facilitating self-reflection. The design choices are further discussed in respect to interviews of ten news media experts. The findings are reflected against the question of how can critique meaningfully manifest in this challenging problem area.

Vibrotactile feedback is widely used in mobile devices because it provides a discreet and private feedback channel. Gaze-based interaction, on the other hand, is useful in various applications due to its unique capability to convey the focus of interest. Gaze input is naturally available as people typically look at things they operate, but feedback from eye movements is primarily visual. Gaze interaction and the use of vibrotactile feedback have been two parallel fields of human–computer interaction research with a limited connection. Our aim was to build this connection by studying the temporal and spatial mechanisms of supporting gaze input with vibrotactile feedback. The results of a series of experiments showed that the temporal distance between a gaze event and vibrotactile feedback should be less than 250 ms to ensure that the input and output are perceived as connected. The effectiveness of vibrotactile feedback was largely independent of the spatial body location of vibrotactile actuators. In comparison to other modalities, vibrotactile feedback performed equally to auditory and visual feedback. Vibrotactile feedback can be especially beneficial when other modalities are unavailable or difficult to perceive. Based on the findings, we present design guidelines for supporting gaze interaction with vibrotactile feedback.

In gesture-based user interfaces, the effort needed for learning the gestures is a persistent problem that hinders their adoption in products. However, people's natural gaze paths form shapes during viewing. For example, reading creates a recognizable pattern. These gaze patterns can be utilized in human-technology interaction. We experimented with the idea of inducing specific gaze patterns by static drawings. The drawings included visual hints to guide the gaze. By looking at the parts of the drawing, the user's gaze composed a gaze gesture that activated a command. We organized a proof-of-concept trial to see how intuitive the idea is. Most participants understood the idea without specific instructions already on the first round of trials. We argue that with careful design the form of objects and especially their decorative details can serve as a gaze-based user interface in smart homes and other environments of ubiquitous computing.

An emerging use of mobile video telephony is to enable joint activities and collaboration on physical tasks. We conducted a controlled user study to understand if seeing the gaze of a remote instructor is beneficial for mobile video collaboration and if it is valuable that the instructor is aware of sharing of the gaze. We compared three gaze sharing configurations, (a) Gaze_Visible where the instructor is aware and can view own gaze point that is being shared, (b) Gaze_Invisible where the instructor is aware of the shared gaze but cannot view her own gaze point and (c) Gaze_Unaware where the instructor is unaware about the gaze sharing, with a baseline of shared-mouse pointer. Our results suggests that naturally occurring gaze may not be as useful as explicitly produced eye movements. Further, instructors prefer using mouse rather than gaze for remote gesturing, while the workers also find value in transferring the gaze information.

Exploratory analysis of gaze data requires methods that make it possible to process large amounts of data while minimizing human labor. The conventional approach in exploring gaze data is to construct heatmap visualizations. While simple and intuitive, conventional heatmaps do not clearly indicate differences between groups of viewers or give estimates for the repeatability (i.e., which parts of the heatmap would look similar if the data were collected again). We discuss difference maps and significance maps that answer to these needs. In addition we describe methods based on automatic clustering that allow us to achieve similar results with cluster observation maps and transition maps. As demonstrated with our example data, these methods are effective in highlighting the strongest differences between groups more effectively than conventional heatmaps.

The aim was to study if odors evaporated by an olfactory display prototype can be used to affect participants' cognitive and emotionrelated responses to audio-visual stimuli, and whether the display can benefit from objective measurement of the odors. The results showed that odors and videos had significant effects on participants' responses. For instance, odors increased pleasantness ratings especially when the odor was authentic and the video was congurent with odors. The objective measurement of the odors was shown to be useful. The measurement data was classified with 100% accuracy removing the need to speculate whether the odor presentation apparatus is working properly.

Remote collaboration on physical tasks is an emerging use of video telephony. Recent work suggests that conveying gaze information measured using an eye tracker between collaboration partners could be beneficial in this context. However, studies that compare gaze to other pointing mechanisms, such as a mouse-controlled pointer, in video-based collaboration, have not been available. We conducted a controlled user study to compare the two remote gesturing mechanisms (mouse, gaze) to video only (none) in a situation where a remote expert saw video of the desktop of a worker where his/her mouse or gaze pointer was projected. We also investigated the effect of distraction of the remote expert on the collaborative process and whether the effect depends on the pointing device. Our result suggests that mouse and gaze pointers lead to faster task performance and improved perception of the collaboration, in comparison to having no pointer at all. The mouse outperformed the gaze when the task required conveying procedural instructions. In addition, using gaze for remote gesturing required increased verbal effort for communicating both referential and procedural messages.

Video communication using head-mounted cameras could be useful to mediate shared activities and support collaboration. Growing popularity of wearable gaze trackers presents an opportunity to add gaze information on the egocentric video. We hypothesized three potential benefits of gaze-augmented egocentric video to support collaborative scenarios: support deictic referencing, enable grounding in communication, and enable better awareness of the collaborator's intentions. Previous research on using egocentric videos for real-world collaborative tasks has failed to show clear benefits of gaze point visualization. We designed a study, deconstructing a collaborative car navigation scenario, to specifically target the value of gaze-augmented video for intention prediction. Our results show that viewers of gaze-augmented video could predict the direction taken by a driver at a four-way intersection more accurately and more confidently than a viewer of the same video without the superimposed gaze point. Our study demonstrates that gaze augmentation can be useful and encourages further study in real-world collaborative scenarios.

In a study with 12 participants we compared two smooth pursuit based widgets and one dwell time based widget in adjusting a continuous value. The circular smooth pursuit widget was found to be about equally efficient as the dwell based widget in our color matching task. The scroll bar shaped smooth pursuit widget exhibited lower performance and lower user ratings.

Communicating spatial information by pointing is ubiquitous in human interactions. With the growing use of head-mounted cameras for collaborative purposes, it is important to assess how accurately viewers of the resulting egocentric videos can interpret pointing acts. We conducted an experiment to compare the accuracy of interpreting four different pointing techniques: hand pointing, head pointing, gaze pointing and hand+gaze pointing. Our results suggest that superimposing the gaze information on the egocentric video can enable viewers to determine pointing targets more accurately and more confidently. Hand pointing performed best when the pointing target was straight ahead and head pointing was the least preferred in terms of ease of interpretation. Our results can inform the design of collaborative applications that make use of the egocentric view.

The best way to construct user interfaces for smart glasses is not yet known. We investigated the use of eye tracking in this context in two experiments. The eye and head movements were combined so that one can select the object to interact by looking at it and then change a setting in that object by turning the head horizontally. We compared three different techniques for mapping the head turn to scrolling a list of numbers with and without haptic feedback. We found that the haptic feedback had no noticeable effect in objective metrics, but it sometimes improved user experience. Direct mapping of head orientation to list position is fast and easy to understand, but the signal-to-noise ratio of eye and head position measurement limits the possible range. The technique with constant rate of change after crossing the head angle threshold was simple and functional, but slow when the rate of change is adjusted to suit beginners. Finally the rate of change dependent on the head angle tends to lead to fairly long task completion times, although in theory it offers a good combination of speed and accuracy.

Digitalization is changing how research is carried out in all areas of science. Humanities is no exception - materials that used to be hand-written or printed on paper are increasingly available in digital form. This development is changing how scholars are interacting with their material. We are addressing the problem of interactive text visualization in the context of sociolinguistic language study. When a scholar is reading and analyzing text from a computer screen instead of a paper, we can support this by providing a dashboard for reading, and by creating visualizations of the text structure, variation, and change. We have designed and developed a software tool called Text Variation Explorer (TVE) for sociolinguistic language study. It is based on interactive visualization with a direct manipulation user interface, and aimed for exploratory corpus linguistics. The TVE software tool has proven to be useful in supporting the study of language variation and change in its social contexts, or sociolinguistics. It is, to a certain degree, language-independent, and generic enough to be useful in other linguistic contexts as well. We are now in the process of designing and implementing the next iteration of TVE. We present the lessons learned from the first version, discuss the old and the new design, and welcome feedback from the communities involved.

Modern interaction techniques like non-intrusive gestures provide means for interacting with distant displays and smart objects without touching them. We were interested in the effects of feedback modality (auditory, haptic or visual) and its combined effect with input modality on user performance and experience in such interactions. Therefore, we conducted two exploratory experiments where numbers were entered, either by gaze or hand, using gestures composed of four stroke elements (up, down, left and right). In Experiment 1, a simple feedback was given on each stroke during the motor action of gesturing: an audible click, a haptic tap or a visual flash. In Experiment 2, a semantic feedback was given on the final gesture: the executed number was spoken, coded by haptic taps or shown as text. With simultaneous simple feedback in Experiment 1, performance with hand input was slower but more accurate than with gaze input. With semantic feedback in Experiment 2, however, hand input was only slower. Effects of feedback modality were of minor importance; nevertheless, semantic haptic feedback in Experiment 2 showed to be useless at least without extensive training. Error patterns differed between both input modes, but again not dependent on feedback modality. Taken together, the results show that in designing gestural systems, choosing a feedback modality can be given a low priority; it can be chosen according to the task, context and user preferences.

The QWERTY keyboard has been a de facto standard for computer text entry and continues to be one for mobile text entry such as for smartphones. It is not clear, however, that it will continue to be an option for text entry for much smaller devices such as smartwatches. In a series of user experiments, we examined the performance of the QWERTY keyboard when it is reduced to fit a small smartwatch screen. At the same time, we examined whether the ZoomBoard and the SplitBoard, which are QWERTY keyboards augmented by zooming and panning strategies, respectively, would be effective in comparison with a plain QWERTY keyboard. In Experiment 1, we evaluated the text entry performance of new users on the three QWERTY keyboards. In Experiment 2, we evaluated the relative performance of the three keyboards for three different screen sizes. In Experiment 3, we further observed how the keyboard performance changed when used in a mobile situation. Main results are: (i) users could adapt to a plain QWERTY keyboard even in the smallest screen cases. (ii) The SplitBoard consistently showed a better performance than other keyboards in all tested sizes. (iii) The SplitBoard showed a better performance than other keyboards in a mobile condition (treadmill) and was preferred most by participants.

Text entry on a smartwatch is a challenging problem due to the device's limited screen area. In this paper, we introduce the SplitBoard, which is a soft keyboard designed for a smartwatch. As the user flicks left or right on the keyboard, it switches between the left and right halves of a QWERTY keyboard. We report the results of two user experiments where the SplitBoard was compared to an ordinary QWERTY keyboard, the ZoomBoard, SlideBoard, and Qwerty-like keypad. We measured the initial performance with new users for each method. The SplitBoard outperformed all other techniques in the experiments. The SplitBoard is expected to be a viable option for smartwatch text entry because of its light processing requirements, good performance, and immediate learnability.

Interacting with the environment using mobile eye-tracking is accompanied with challenges in providing non-visual feedback related to gaze events and monitoring the gaze vector estimation quality. Recent studies point to haptic stimulation as a promising feedback channel in this context. In this work we focused on applying haptic stimulation to inform users of pointing inaccuracies by cuing their gaze in the direction of nearby interactive objects. To decrease the cognitive load, short repetitive vibrations from four actuators were applied to the head and neck of the user. The head area stimulation was compared to the back that has often been used in earlier studies. The results showed that the haptic stimulation on the head and neck cued users as efficiently as the stimulation of the back, although smaller stimulation signal amplitude would be desirable. Another important implication refers to the design of the stimulation signal pattern: if multiple actuators are used in stimulation, then they should be activated sequentially and not simultaneously.

Virtual and physical worlds are merging. Currently users of head-mounted displays cannot have unobtrusive tactile feedback while touching virtual objects. We present a mid-air tactile feedback system for head-mounted displays. Our prototype uses the focus of a modulated ultrasonic phased array for unobtrusive mid-air tactile feedback generation. The array and the hand position sensor are mounted on the front surface of a head-mounted virtual reality display. The presented system can enhance 3D user interfaces and virtual reality in a new way.

Anticipating the emergence of gaze tracking capable mobile devices, we are investigating the use of gaze as an input modality in handheld mobile devices. We conducted a study of combining gaze gestures with vibrotactile feedback. Gaze gestures were used as an input method in a mobile device and vibrotactile feedback as a new alternative way to give confirmation of interaction events. Our results show that vibrotactile feedback significantly improved the use of gaze gestures. The tasks were completed faster and rated easier and more comfortable when vibrotactile feedback was provided.

Consistent measuring and reporting of gaze data quality is important in research that involves eye trackers. We have developed TraQuMe: a generic system to evaluate the gaze data quality. The quality measurement is fast and the interpretation of the results is aided by graphical output. Numeric data is saved for reporting of aggregate metrics for the whole experiment. We tested TraQuMe in the context of a novel hidden calibration procedure that we developed to aid in experiments where participants should not know that their gaze is being tracked. The quality of tracking data after the hidden calibration procedure was very close to that obtained with the Tobii's T60 trackers built-in 2 point, 5 point and 9 point calibrations.

Eye tracking input often relies on visual and auditory feedback. Haptic feedback offers a previously unused alternative to these established methods. We describe a study to determine the natural time limits for haptic feedback to gazing events. The target is to determine how much time we can use to evaluate the user gazed object and decide if we are going to give the user a haptic notification on that object or not. The results indicate that it is best to get feedback faster than in 250 milliseconds from the start of fixation of an object. Longer delay leads to increase in incorrect associations between objects and the feedback. Delays longer than 500 milliseconds were confusing for the user.

Compared to the mouse, eye pointing is inaccurate. As a consequence, small objects are difficult to point by gaze alone. We suggest using a combination of eye pointing and subtle head movements to achieve accurate hands-free pointing in a conventional desktop computing environment. For tracking the head movements, we exploited information of the eye position in the eye tracker's camera view. We conducted a series of three experiments to study the potential caveats and benefits of using head movements to adjust gaze cursor position. Results showed that head-assisted eye pointing significantly improves the pointing accuracy without a negative impact on the pointing time. In some cases participants were able to point almost 3 times closer to the target's center, compared to the eye pointing alone (7 vs. 19 pixels). We conclude that head assisted eye pointing is a comfortable and potentially very efficient alternative for other assisting methods in the eye pointing, such as zooming.

We describe the design and evaluation of a gestural text editing technique for touchscreen devices. The gestures are drawn on top of the soft keyboard and interpreted as commands for moving the caret, performing selections, and controlling the clipboard. Our implementation is an Android service that can be used in any text editing task on Android-based devices. We conducted an experiment to compare the gestural editing technique against the widget-based technique available on a smartphone (Samsung Galaxy II with Android 2.3.5). The results show a performance benefit of 13-24% for the gestural technique depending on the font size. Subjective feedback from the participants was also positive. Because the two editing techniques use different input areas, they can co-exist on a device. This means that the gestural editing can be added on any soft keyboard without interfering with user experience for those users that choose not to use it.

Edgewrite is a text entry method where the user follows the edges of a physical guiding rectangle to enter corner sequences that are interpreted as characters. The original Edgewrite character set resembles the Latin alphabet and includes explicit character segmentation by lifting the stylus (or centering the joystick, etc). We present a variant of Edgewrite that we call the continuous Edgewrite. It relies on a dictionary instead of user's character segmentation to disambiguate words. New users can use the continuous Edgewrite with the help of an interactive visualization of possible continuations while writing. In a 6-session user study we measured initial text transcription performance (increased from 1 to 5.4 wpm) and the ratio of observed explicit segmentations to optimal continuous writing (decreased from 2.5 to 1.5). These results show that it is possible to learn to use the continuous writing mode, but also that the learning takes some time.

We evaluated two cursor designs in the continuum between the traditional point cursor and the bubble cursor by Grossman and Balakrishnan. The lazy bubble cursor expanded to envelop the closest target when the ratio of the distances to the closest and the second closest target was less than 1:2. In addition to this lazy behavior the cone cursor had a tail that stayed on the last enveloped target until the next target was enveloped. In an experiment with 18 participants we found that the bubble cursor was faster than our cursors that had smaller target activation areas but the difference remained very small. Of the bubble cursor variants the lazy bubble exhibited higher error rate than the other two. Thus, the winners on the objective metrics were the bubble cursor and the cone cursor. The lazy bubble cursor and the bubble cursor were preferred in subjective ratings.

We describe an experiment to test the hypothesis that Fitts' throughput is independent of the speed-accuracy tradeoff. Eighteen participants used a mouse in performing a total of 5,400 target selection trials. Comparing nominal, speed-emphasis, and accuracy-emphasis conditions, significant main effects were found on movement time (ms) and error rate (%), but not on throughput (bits/s). In the latter case, failure to reject the null hypothesis of "no significant difference" (i.e., .05 < p < 1) is viewed as evidence supporting the constant-throughput hypothesis.

We describe a system that informs the users of the shape of the EdgeWrite characters within the visual feedback area of EdgeWrite. We compared two versions (static and dynamic) of this design to a printed character chart in a five-session text entry experiment with three 8-participant groups. The participants were able to use EdgeWrite with the integrated help systems. There were no statistically significant differences in text entry rate between the group using the character chart and the two groups using the integrated help. However, the group with the dynamic help was faster than the group with the static help while maintaining a low corrected error rate.

Dasher is one of the best known inventions in the area of text entry in recent years. It can be used with many input devices, but studies on user performance with it are still scarce. We ran a longitudinal study where 12 participants transcribed Finnish text with Dasher in ten 15-minute sessions using a Tobii 1750 eye tracker as a pointing device. The mean text entry rate was 2.5 wpm during the first session and 17.3 wpm during the tenth session. Our results show that very high text entry rates can be achieved with eye-operated Dasher, but only after several hours of training.

We report the design and evaluation of a novel game controller text entry method called TwoStick. The design is based on the review of previous work and several rounds of pilot testing. We compared user performance with TwoStick experimentally to a selection keyboard which is the de facto standard of game controller text entry. Eight participants completed 20 fifteen-minute sessions with both text entry methods. In the beginning TwoStick was slower (4.3 wpm, uncorrected error rate = 0.68%) than the selection keyboard (5.6 wpm, 0.85%). During the last session TwoStick was faster (14.9 wpm, 0.86% vs. 12.9 wpm, 0.27%). Qualitative results indicated that TwoStick was more fun and easier to use than the selection keyboard.

Trackball-mice are devices that include both a trackball and a mouse. In this paper we discuss our experiences in building and testing trackball-mouse prototypes. We report four experiments on user performance with the prototypes used as trackball-mice, conventional mice, and in two-handed configuration with a separate trackball for the non-dominant hand. The results show that user performance with the two-handed configuration was better than in one-handed operation of a trackball-mouse and in one-handed operation of a mouse. Trackball-mouse use and conventional mouse use were more evenly matched. However, Trackball-mouse operation involves a skill that most users do not have whereas mouse operation is familiar to most. Therefore, widespread introduction of trackball-mice does not appear to be justified on performance grounds alone. However, trackball-mice can be used as regular mice by ignoring the ball. This makes them compatible with traditional graphical user interfaces while offering two extra degrees of freedom in tasks where they are beneficial.

We report results on the performance of the combination of soft keyboards and marking menus. A model of expert user performance indicated an 11 - 37% (depending on the keyboard layout) improvement in text entry rate over the same keyboard without the menu. To verify the advantage in real usage, we conducted two experiments using the QWERTY keyboard layout with and without the menu. The first experiment imitated nearly perfect cognitive performance and measured motor performance. Using the menu saved time. The second experiment measured performance in a realistic text entry task. Initially using the menu slows down text entry. By the end of the 20-session experiment both conditions were equally fast. With continued practice text entry is likely to be faster with the menu.

The present aim was to study a new technique for human--computer interaction. It combined the use of two modalities, voluntary gaze direction and voluntary facial muscle activation for object pointing and selection. Fourteen subjects performed a series of pointing tasks with the new technique and with a mouse. At short distances the mouse was significantly faster than the new technique. However, there were no statistically significant differences at medium and long distances between the techniques. Fitts' law analyses were performed both by using only error-free trials and using also data including error trials (i.e., effective target width). In all cases both techniques seemed to follow Fitts' law, although for the new technique the effective target width correlation coefficient was smallerR= 0.776 than for the mouseR= 0.991. The regression slopes suggested that at very long distances (i.e., beyond 800 pixels) the new technique might be faster than the mouse. The new technique showed promising results already after a short practice and in the future it could be useful especially for physically challenged persons.

Small hand-held touchpads can be used to replace stylus-based digitizing tablets when the use of a stylus is not convenient. In text entry tasks where the writing surface is held in a hand the error rate becomes a problem. The small size of strokes compared to the width of the fingertip and the additional imprecision caused by the interaction of the pad and finger movements make input very imprecise. We describe a new improved clock-face based stroke system for entering numbers with a touchpad. In a 20-session user study with 6 users we found slightly better throughput of successfully entered numbers with the proposed new system. This advantage was mainly due to lower error rate with the new system. User preference similarly slightly favored the new system over an earlier straightforward proposal based on the clock metaphor

Unistrokes are a viable form of text input in pen-based user interfaces. However, they are a very heterogeneous group of gestures the only common feature being that all are drawn with a single stroke. Several unistroke alphabets have been proposed including the original Unistrokes, Graffiti, Allegro, T-Cube and MDITIM. Comparing these methods usually requires a lengthy study with many writers and even then the results are biased by the earlier handwriting experience that the writers have. Therefore, a simple descriptive model can make these comparisons easier. In this paper we propose a model for predicting the writing time for an expert user on any given unistroke alphabet thus enabling sounder argumentation on the properties of different writing methods. Keywords Modeling of motor performance, handwriting, pen input INTRODUCTION Unistrokes were introduced as a text input method for penbased user interfaces by Goldberg and Richardson in their 1993 paper [8]. Unistrokes are an alte...

Individual characters and text are the main inputs in many computing devices. Currently there is a growing trend in developing small portable devices like mobile phones, personal digital assistants, GPS-navigators, and two-way pagers. Unfortunately these portable computing devices have different user interfaces and therefore the task of text input takes many forms. The user, who in the future is likely to have several of these devices, has to learn several text input methods. We argue that there is a need for a universal text input method. A method like this would work on a wide range of interface technologies and allow the user to transfer his or her writing skill without device-specific training. To show that device independent text input is possible, we present a candidate for a device independent text entry method that supports skill transfer between different devices. A limited longitudinal study was conducted to achieve a proof of concept evaluation of our Minimal Device Independent Text Input Method (MDITIM). We found MDITIM writing skill acquired with a touchpad to work almost equally well on mouse, trackball, joystick and keyboard without any additional training. Our test group reached on average 41% of their handwriting speed by the end of the tenth 30-minute training session.

Text input with eye trackers can be implemented in many ways such as on-screen keyboards or context sensitive menu-selection techniques. We propose the use of off-screen targets and various schemes for decoding target hit sequences into text. Off-screen targets help to avoid the Midas' touch problem and conserve display area. However, the number and location of the off-screen targets is a major usability issue. We discuss the use of Morse code, our Minimal Device Independent Text Input Method (MDITIM), QuikWriting, and Cirrin-like target arrangements. Furthermore, we describe our experience with an experimental system that implements eye tracker controlled MDITIM for the Windows environment.