We present an investigation of sharing the focus of visual attention between two players in a collaborative game, so that where one player was looking was visible to the other. The difference between using head-gaze and eye-gaze to estimate the point of regard was studied, the motive being that recording head-gaze is easier and cheaper than eye-gaze. Two experiments are reported, the first investigates the effect of a high immersion presentation of the game in VR Head Mounted Display compared with a lower immersion desktop presentation. The second examines the high immersion condition in more detail. The studies show that in spite of there being many factors that could affect the outcome of a relatively short period of game play, sharing eye-gaze in the high immersion condition produces shorter overall durations and better subjective ratings of team work than does sharing head-gaze. This difference is not apparent in the low immersion condition. The findings are a good argument for exploiting the opportunities for including and using eye tracking within head mounted displays in the context of collaborative games.

Collaboration improves efficiency, avoids duplication of efforts, improves goal-awareness, and makes working generally more pleasurable. While collaboration is desirable, it introduces additional costs because of the required coordination. In this article, we study how visual search is affected by gaze-sharing collaboration. There is evidence that pairs of visual searchers using gaze-only sharing are more efficient than single searchers. We extend this result by investigating if groups of three searchers are more efficient, and if and how the groups of searchers develop their search strategy. We conducted an experiment to understand how the collaboration develops when groups of one to three participants perform a visual search task by collaborating with shared gaze. The task was to state if the target was present among distractors. Our results show that users are able to develop an efficient search and division-of-labor strategy when the only collaboration method is gaze-sharing.

To use eye trackers in a school classroom, children need to be able to calibrate their own tracker unsupervised and on repeated occasions. A game designed specifically around the need to maintain their gaze in fixed locations was used to collect calibration and verification data. The data quality obtained was compared with a standard calibration procedure and another game, in two studies carried out in three elementary schools. One studied the effect on data quality over repeated occasions and the other studied the effect of age on data quality. The first showed that accuracy obtained from unsupervised calibration by children was twice as good after six occasions with the game requiring the fixed gaze location compared with the standard calibration, and as good as standard calibration by group of supervised adults. In the second study, age was found to have no effect on performance in the groups of children studied.

In curriculum visualization, information visualization techniques are used to communicate the structure and content of a curriculum to the stakeholders, such as students, lecturers, and administrators. Curriculum visualization has recently drawn a lot of interest as there are growing demands to form larger educational units and to find savings by eliminating overlap. We have developed a novel approach to analyse and visualize the contents of a curriculum. Our software tool for curriculum visualization uses a fast heuristic to automatically lay out a curriculum diagram, provides tools to process the content information, and offers several coordinated views to visualize the curriculum contents and overlap. The approach and software tool have already been used successfully in one survey and two others are underway.

Although eye typing (typing on an on-screen keyboard via one's eyes as they are tracked by an eye tracker) has been studied for more than three decades now, we still know relatively little about it from the users' point of view. Standard metrics such as words per minute and keystrokes per character yield information only about the effectiveness of the technology and the interaction techniques developed for eye typing. We conducted an extensive study with almost five hours of eye typing per participant and report on extended qualitative and quantitative analysis of the relationship of dwell time, text entry rate, errors made, and workload experienced by the participants. The analysis method is comprehensive and stresses the need to consider different metrics in unison. The results highlight the importance of catering for individual differences and lead to suggestions for improvements in the interface.

We created a set of gaze gestures that utilize the following three elements: simple one-segment gestures, off-screen space, and the closure of the eyes. These gestures are to be used as the moving tool in a gaze-only controlled drawing application. We tested our gaze gestures with 24 participants and analyzed the gesture durations, the accuracy of the stops, and the gesture performance. We found that the difference in gesture durations between short and long gestures was so small that there is no need to choose between them. The stops made by closing both eyes were accurate, and the input method worked well for this purpose. With some adjustments and with the possibility for personal settings, the gesture performance and the accuracy of the stops can become even better.

Several enhanced pointing techniques aim to reduce the Fitts' law targeting distance by providing multiple target trajectories in the hope that a shorter path is available. However, these techniques introduce a search or decision component to pointing users must examine the alternatives available and decide upon the trajectory to use. We analyse these difficulties, present a methodology for examining them as well as other behaviour issues, and report empirical results of performance with pointer wrapping and Ninja cursors. Results show that offering multiple trajectories incurs a significant search or decision cost, and that users are therefore poor at capitalising on the theoretical benefits of reduced target distance.

Chinese text entry on mobile phones is critical considering the large number of Chinese speakers worldwide and as a key task in many core applications. But there is still a lack of both empirical data and predictive models that explore the pattern of user behavior in the process. We propose a model to predict user performance with two types of Chinese pinyin input methods on mobile phones. The model integrates a language model (digraph probability) with Fitts' law for key presses, a keystroke-level model for navigation, and a linear model for visual search in pinyin marks and Chinese characters. We tested the model by comparing its predictions with the empirical measures. The predictions are satisfactory and the percentage differences are all within 4% of the empirical results, suggesting that the model can be used to evaluate user performance of Chinese pinyin text entry solutions on mobile phones.

Awareness of shared work activities is important for fostering professional relationships. This paper introduces visualization techniques for a meeting support system based on automatic speech recognition and multisensory meeting information capture, including voice levels and participant comments. The system has been deployed in live meetings over the past 5 months and we report meeting participants’ expectations and findings from a field study. Initial findings suggest that the proposed approach can facilitate awareness without the need for detailed meeting transcriptions and associated audio recordings, however the quality of speech recognition results and their effective visualization remain critical factors for increased adoption.

Abstract Emotion‐ and attention‐related subjective and physiological responses to virtual proximity and facial expressions of embodied computer agents (ECA) were studied. Thirty participants viewed female and male characters with a neutral, unpleasant, or pleasant facial expression. Agents' size was used to simulate three levels of proximity. Participants' electrical facial muscle and heart activity were registered, and subjective ratings of emotional and attentional experiences collected. Unpleasant and large (i.e., closer) agents were more alerting (i.e., unpleasant, arousing, and dominating) and attracted more stimulus‐driven attention than neutral, pleasant, and smaller (i.e., further away) agents. Pleasant agents attracted more voluntary attention than neutral and unpleasant agents. Heart rate (HR) responded to agent proximity, while the valence of the agent affected electrical facial muscle activity. Thus, the imitation of human social emotional cues in embodied computer agents (ECAs) could be used to regulate human–computer interaction. Copyright © 2010 John Wiley & Sons, Ltd.

Ninja cursors aim to speed up target selection on large or multiple monitors. Several cursors are displayed on the screen with one of them selected as the active cursor. Eye tracking is used to choose the active cursor. An experiment with 13 participants showed that multiple cursors speed up the selection over long distances, but not over short distances. Participants felt the technique was fastest with 4 cursors per monitor, but still preferred to have only 1 cursor per monitor for their own use.

Parallel coordinates is a visualization technique that provides an unbiased representation of high-dimensional data. The parallel configuration of axes treats data dimensions uniformly and is well suited for exploratory visualization. However, first-time users of parallel coordinate visualizations can find the representation confusing and difficult to understand.We used eye tracking to study how parallel coordinate visualizations are perceived, and compared the results to the optimal visual scan path required to complete the tasks. The results indicate that even first-time users quickly learn how to use parallel coordinate visualizations, pay attention to the correct task-specific areas in the visualization, and become rapidly proficient with it.

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 tracked the eye movements of 18 students as they translated three short texts with different complexity levels under three different time constraints. Participants with touch typing skills were found to attend more to on-screen text than participants without touch typing skills. Time pressure was found to mainly affect fixations on the source text, and text complexity was found to only affect the number of fixations on the source text. Overall, it was found that average fixation duration was longer in the target text area than in the source text area.

The increase in usage of eye-tracking technology to study text translation processes has revealed the need for effective tools for visualization of the data collected. We propose a new method for gaze and keystroke data visualization. The visualization utilizes the preprocessed gaze data, where detected fixations are linked to the corresponding word in the text. The blocks of reading and typing processes are shown in parallel with details for each word presented in word bars. Reading or typing sequences provide insight into the temporal distribution of the subject's activity, and highlighting pops up the unusual or attention-requiring data and events.

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.

The aim in this work was to develop a method to visualize log files produced by a pilot study of an experimental e-learning platform. The e-learning system running on a web server generated detailed descriptions of its usage that were analyzed. The log files were produced to allow the project's researchers to study offline how the system was utilized. We used open-source software tools to create a flexible system that processed a large amount of log data into concise visual representations. The visualizations revealed a set of different interaction patterns during the pilot study and showed that each teacher had a large effect on students' interaction with the system. Thus, the results showed that the suggested visualization method can be used to support the evaluation and training of students' proficiency in a learning environment.

Chinese text entry solutions for mobile phones are critical, since they get used by most Chinese mobile phone users every day. We designed two new solutions for Chinese pinyin text entry with a rotator as input device. They were evaluated in an empirical study with 12 novice users and compared to a straightforward implementation of the date stamp method. Although there was no significant difference between the three designs on user performance, the perceived efficiency by users was higher for one of the new designs, and it was their technique of choice for their own phone. Because the evaluation setup favored the date stamp method (it was the only one supporting predictive input, and also the most familiar to users), the results are encouraging. We close by discussing how to further develop the new techniques.

We studied user behavior in a recommender-rich environment, Amazon online store, to see what role the algorithm-based and user-generated recommendations play in finding items of interest. We used applied ethnography, on-location interviewing and observation, to get an accurate picture of user activity. We were especially interested in the role of customer ratings and reviews and what kind of strategies users had developed for such an environment. Our results underline the need to develop recommender systems as a whole. The way the recommendations are shown affects which items get picked, and for improving the interface, it is necessary to study the whole in addition to studying the parts in isolation.

Parallel coordinate visualizations have a reputation of being difficult to understand, expert-only representations. We argue that this reputation may be partially unfounded, because many of the parallel coordinate browser implementations lack essential features. This paper presents a survey of current interaction techniques for parallel coordinate browsers and compares them to the visualization design guidelines in the literature. In addition, we report our experiences with parallel coordinate browser prototypes, and describe an experiment where we studied the immediate usability of parallel coordinate visualizations. In the experiment, 16 database professionals performed a set of tasks both with the SQL query language and a parallel coordinate browser. The results show that although the subjects had doubts about the general usefulness of the parallel coordinate technique, they could perform the tasks more efficiently with a parallel coordinate browser than with their familiar query language interface.

The tutorial provides examples, experiences and design guidelines for using eye-gaze in human-computer interaction. The goal of the tutorial is to give insight into exploiting the information about gaze direction in human-computer interaction. The participants will learn the basics of eye-tracking, but the focus of the tutorial is on the interaction issues. After the tutorial, the participants understand the pros and cons of using gaze for real-time input. The tutorial consists of lectures and live demonstrations with a state-of-the-art eye-tracking device.

Speech-based applications commonly come with web-based or printed manuals. Alternatively, the dialogue can be designed so that users should be able to start using the application on their own. We studied an alternative approach, an integrated tutor. The tutor participates in the interaction when new users learn to use a speech-based system. It teaches the users how to operate the system and monitors user actions to be certain that the users do indeed learn. In this paper we describe our experiences with the design and the iterative development of an integrated tutor. Expert evaluation and two user tests were conducted with different versions of the tutor. The results show that the tutor can effectively guide new users. We identify the six most important lessons learned, the most important being that it is essential to spot problems by monitoring user actions, especially when novice users are tutored.

Eye typing provides means of communication especially for people with severe disabilities. Recent research indicates that the type of feedback impacts typing speed, error rate, and the user's need to switch her gaze between the on-screen keyboard and the typed text field. The current study focuses on the issues of feedback when a short dwell time (450 ms vs. 900 ms in a previous study) is used. Results show that the findings obtained using longer dwell times only partly apply for shorter dwell times. For example, with a short dwell time, spoken feedback results in slower text entry speed and double entry errors. A short dwell time requires sharp and clear feedback that supports the typing rhythm.

Eye typing provides a means of communication for severely handicapped people, even those who are only capable of moving their eyes. This paper considers the features, functionality and methods used in the eye typing systems developed in the last twenty years. Primary concerned with text production, the paper also addresses other communication related issues, among them customization and voice output.

Eye-aware applications have existed for long, but mostly for very special and restricted target populations. We have designed and are currently implementing an eye-aware application, called iDict, which is a general-purpose translation aid aimed at mass markets. iDict monitors the user's gaze path while s/he is reading text written in a foreign language. When the reader encounters difficulties, iDict steps in and provides assistance with the translation. To accomplish this, the system makes use of information obtained from reading research, a language model, and the user profile. This paper describes the idea of the iDict application, the design problems and the key solutions for resolving these problems.

Object alignment is one of the basic operations in drawing programs. Current solutions provide mainly three ways for carrying out this operation: either by issuing an alignment command, or by using direct positioning with the help of gravity active points, or by making use of constraints. The first technique has limited functionality, and the other two may be difficult to learn for a novice. We describe here a new direct manipulation tool for alignment. We show that while direct manipulation helps to make the normal use of the tool intuitive, it also offers advanced functionality not found in current commercial products. We report on an empirical study in which we compared the ease of use, intuitiveness, learnability, and efficiency of alignment menus, palettes and the alignment stick. In the study novice users found the basic operation of the alignment stick natural and easy to learn. The increased functionality was best appreciated and utilized by the experienced users.

In modern graphical user interfaces pull-down menus are one of the most frequently used components. But still after years of research there is no clear evidence on how the users carry out the visual search process in pull-down menus. Several models have been proposed for predicting selection times. However, most observations are based only on execution times and cannot therefore explain where the time is spent. The few models that are based on eye movement research are conflicting. In this study we present an experiment where eye movement data was gathered in a menu usage task. By analyzing the scan paths of the eye, we found that menus are read in sequential sweeps. This may explain why the best models produced by previous research are hybrid models that combine systematic reading behavior with random reading behavior. Keywords Menu selection, visual search process, eye movement, eye tracking INTRODUCTION Pull-down menus (also known as drop-down menus) form one of the key componen...

Current drawing programs provide mainly three ways for carrying out object alignment: either by issuing an alignment command, or by using direct positioning with the help of gravity active points, or by making use of constraints.The first technique has limited functionality, and the other two may be mysterious for a novice.We describe here a new direct manipulation tool for alignment.We show that while direct manipulation helps to make the tool intuitive, it has through iterative design evolved into a tool that also offers functionality not found in current commercial products.

We consider the problem of discovering the functional and inclusion dependencies that a given database instance satisfies. This technique is used in a database design tool that uses example databases to give feedback to the designer. If the examples show deficiencies in the design, the designer can directly modify the examples. the tool then infers new dependencies and the database schema can be modified, if necessary. the discovery of the functional and inclusion dependencies can also be used in analyzing an existing database. the problem of inferring functional dependencies has several connections to other topics in knowledge discovery and machine learning. In this article we discuss the use of examples in the design of databases, and give an overview of the complexity results and algorithms that have been developed for this problem. © 1992 John Wiley & Sons, Inc.

Several decision problems for relational schemas with functional dependencies are computationally hard. Such problems include determining whether an attribute is prime and testing if a schema is in normal form. Algorithms for these problems are needed in database design tools. The problems can be solved by trivial exponential algorithms. Although the size of the instance is usually given by the number of attributes and hence is fairly small, such exponential algorithms are not usable for all design tasks. We give algorithms for these problems whose running time is polynomial in the number of maximal sets not determining an attribute or, equivalently, the number of generators of the family of closed attribute sets. There is theoretical and practical evidence that this quantity is small for the schemas occurring in practice and exponential only for pathological schemas. The algorithms are simple to implement and fast in practice. They are in use in the relational database design tool Design-By-Example.

A transaction model for relational databases is presented. The model is more realistic than the traditional entity based model, since it takes into consideration the special information available in the relational model and in the transactions of a given transaction set. Therefore the model can serve as the basis of an implementation, unlike in the present situation, where implementations must rely on ad hoc techniques or physical level concepts. A concurrency control method is developed based on the transaction model. The method is reminiscent of precision locking, but again it is tailored for the relational model. An efficient implementation of the method is outlined.

A design methodology for relational databases is developed. The main aspects of the methodology are the following. (a) It uses functional dependencies and inclusion dependencies. The latter are essential to model properly e.g. isa-relationships. (b) It is incremental: the database scheme evolves step by step as new information is considered. (c) It is based on an interaction between the designer and a tool that implements the methodology. The basis of the methodology is a normal form for schemes with functional dependencies and inclusion dependencies. Transformations for incrementally changing a scheme into normal form are given.

An automatic technique for generating a comprehensive test database for a given query is studied.The test database is large enough to cover all essentially different situations under the given set of dependencies, and also large enough to illustrate the effect of each operation appearing in the query.On the other hand, the database attempts to do this in a minimal way.The method can be applied in the testing of queries, e.g. as an aid in learning a new query language.The basis of the construction is the definition of an adequate test case.We characterize this concept using Armstrong relations and show that adequate examples have the desired properties.We also give a method for producing reasonably small example databases for select-project-join queries where each relation scheme appears at most once in the query.

Article Free Access Share on Small Armstrong relations for database design Authors: Heikki Mannila View Profile , Kari-Jouko Räihä View Profile Authors Info & Claims PODS '85: Proceedings of the fourth ACM SIGACT-SIGMOD symposium on Principles of database systemsMarch 1985 Pages 245–250https://doi.org/10.1145/325405.325449Published:25 March 1985Publication History 5citation113DownloadsMetricsTotal Citations5Total Downloads113Last 12 Months9Last 6 weeks1 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF

Acyclic database schemes have attracted a lot of interest because of the nice properties enjoyed by such schemes. Recently some new acyclicity conditions that are strictly stronger than the normal α-acyclicity have been introduced by Fagin. Because of increased requirements, the database schemes in the new classes have some further useful properties that are not shared by α-acyclic schemes. Therefore the new classes have practical relevance.A database designer may work in terms of attribute sets and data dependencies, and not only in terms of database schemes. Thus it is important to have a characterization for the acyclic schemes of various degree in terms of data dependencies. For α-acyclic schemes such a characterization exists, but for the new classes the question has been open. In this paper we provide characterizations for β-, γ- and Berge-acyclic database schemes. The characterizations can be stated in a simple form: thus they should be useful for the database designer.

Several online schedulers of transactions are considered. The scheduling algorithms are presented in a modular and uniform way. Deadlock and livelock prevention (using restarts, if necessary) is integrated into the algorithms. A metrics is defined for comparing the behavior of two schedulers on the same set of transactions. The measure that is used makes only a very simple assumption about the transactions. This assumption is easily motivated, and thus the measure is a useful approximation of measures appearing in reality. The behavior of the schedulers is compared on the basis of user delays caused by one scheduler on logs accepted as such by another scheduler. No order of magnitude differences are found, but the examples used for proving lower bounds for the delays are illustrative of the characteristics of the schedulers.

The best known linear-time list marking algorithms also require a linear amount of workspace. Algorithms working in bounded workspace have been obtained only by allowing quadratic execution time or by restricting the list structures to trees. We improve on this here by deriving a new linear-time, bounded workspace marking algorithm that works for dags. The algorithm is derived using correctness-preserving program transformations, which prove the correctness of the algorithm. Our derivation of the marking algorithm provides an example where this method has actually been used to derive a new, more efficient algorithm, rather than just to establish the correctness of a previously known algorithm.

Abstract Automatic production of one‐pass compilers from attribute grammars is considered. An examination of a one‐pass grammar for the programming language Euclid shows that the present definition of one‐pass grammars is too general: the space behaviour of the produced compilers differs from that found in conventional hand‐written compilers. A new class of attribute grammars is defined. The class models naturally the use of space in a hand‐written compiler. This implies that the compiler produced automatically on the basis of the grammar uses space in the same way as a practical hand‐written recursive descent compiler. Furthermore, a graphical notation is introduced as a design tool for obtaining grammars in the proposed class.

The problem of constructing multi-pass evaluators for attribute grammars is studied. We show that the construction algorithm used heretofore can in the worst case produce evaluators which perform $2n - 1$ passes over the parse tree, where n is the minimum number of passes required. Furthermore, the problem of constructing an optimal evaluation order is shown to be NP-complete. We then develop a new characterization for attribute grammars evaluable in passes. It can be directly applied as an efficient membership test. Finally, the characterization is used for deriving a polynomial time construction algorithm for a large subclass of pass-oriented attribute grammars. The subclass is argued to be of practical importance.