International Journal of Human-Computer Interaction

Published by Taylor & Francis
Online ISSN: 1532-7590
Publications
A) Target waveforms for electrode locations Cz, Pz, Po7, and Po8 for each of the 24 participants; PS paradigm data are presented in black and NS paradigm data are presented in grey. (Amplitude units are μV.) B) Grand mean waveforms for all 24 participants at electrode locations Cz, Pz, Po7, and Po8. The top row consists of target responses for both paradigms, and the bottom row consists of non-target responses for both paradigms. PS data is presented in black and NS data is presented in grey.  
Article
This study compared a conventional P300 speller brain-computer interface (BCI) to one used in conjunction with a predictive spelling program. Performance differences in accuracy, bit rate, selections per minute, and output characters per minute (OCM) were examined. An 8×9 matrix of letters, numbers, and other keyboard commands was used. Participants (n = 24) were required to correctly complete the same 58 character sentence (i.e., correcting for errors) using the predictive speller (PS) and the non-predictive speller (NS), counterbalanced. The PS produced significantly higher OCMs than the NS. Time to complete the task in the PS condition was 12min 43sec as compared to 20min 20sec in the NS condition. Despite the marked improvement in overall output, accuracy was significantly higher in the NS paradigm. P300 amplitudes were significantly larger in the NS than in the PS paradigm; which is attributed to increased workload and task demands. These results demonstrate the potential efficacy of predictive spelling in the context of BCI.
 
Article
Exposure to virtual environments often causes users to experience symptoms of motion sickness. An accessory manifestation of motion sickness symptoms is postural disequilibrium. If the postural disequilibrium that occurs persists beyond the time an individual is within the confines of the laboratory or system site, user safety could be compromised and products liability issues could be forthcoming. In this study, a portable, automated postural assessment system is developed that can be employed before and after exposure to a virtual reality (VR) system in order to certify that a user's balance on exiting the system is at least demonstrably as good as it was on entering. It is argued that if the "coming out" balance performance is sufficiently poorer than the "going in" balance, then the user should be retained until the pretest balance performance is regained. The results from a set of normative and validation experiments on postural equilibrium identified several reliable measures of stance that could serve as a basis for certification. Furthermore, a new automated video-based measure using only head movement showed that performance over sessions is stable and reliable. The head movement changes that occur with stimuli, such as alcohol and simulator exposure, are well behaved, predictable, and significant even with small samples. The implication is that the proposed objective measure of postural stability, in conjunction with procedures for obtaining self-reports of symptoms, can afford some measure of certification that exposure to a given VR system is without harm.
 
Conference Paper
Information requirement elicitation (IRE) is essential in wireless Web service to elicit information requirements through interactive choice prompts. We present a design of a high-level user interface for IRE, in the context of 'banking database queries' by a mobile Web user. The prototype is based on the notion of query-by object (QBO) approach of building a query using multiple user-level steps. The test prototype system uses J2ME MIDP for a wireless front end and a J2EE application server and an object-relational database management system (ORDBMS) at the back end. A sample set of queries demonstrate ease of access by the users. Ambiguities in users' intentions are eliminated by virtue of a step-by-step procedure.
 
The working cycle of PolyMorph is split into two phases.  
Mean output characters per minute in-vivo: the times reported for PolyMorph turn 1 and 2 are the means of the spelling times of sentence A and B in turn 1 and turn 2 respectively.
Mean output characters per minute for in-silico experiments when predictions are enabled.
Intensifications per selection and repetition for in-silico experiments when predictions are disabled.  
Article
P300 is an electric signal emitted by brain about 300 milliseconds after a rare, but relevant-for-the-user event. One of the applications of this signal is sentence spelling that enables subjects who lost the control of their motor pathways to communicate by selecting characters in a matrix containing all the alphabet symbols. Although this technology has made considerable progress in the last years, it still suffers from both low communication rate and high error rate. This article presents a P300 speller, named PolyMorph, that introduces two major novelties in the field: the selection matrix polymorphism, that reduces the size of the selection matrix itself by removing useless symbols, and sentence-based predictions, that exploit all the spelt characters of a sentence to determine the probability of a word. In order to measure the effectiveness of the presented speller, we describe two sets of tests: the first one in vivo and the second one in silico. The results of these experiments suggest that the use of PolyMorph in place of the naive character-by-character speller both increases the number of spelt characters per time unit and reduces the error rate.
 
Article
Desktop software agents are background processes that notify a computer user of certain predefined events. The complexity of desktop computing is increasing due to the proliferation of software agents. A Desktop Agent Manager (DAM) may become an important component of desktop computing. This paper focuses on the decision mechanism for the DAM to decide which agents should be allowed to access the user, which agents' results should be stored for future review by the user, and which of the agents should be filtered out. We prove the validity of the concept of a DAM by developing an architecture that includes both a prototype of the Desktop Agent Manager and a simulator of various types of agents. In this paper we present the results of our simulations and analyses of the DAM decision mechanism. 3 1. Introduction There are many applications that reside on the typical office computer: electronic mail, word processor, spreadsheet, personal database manager, corporate database manager, sc...
 
Plausible version space.  
Initial Placement for Company D  
Company E Placement generated by Captain
Reduction of Search Space by Explanations The graph in figure 12 was obtained by averaging the search space obtained for each number of explanations (we found a wide variation of the search space since the individual utility the explanations varied). Figure 12 shows that there is roughly an order of magnitude drop in the search space that the algorithm uses for each explanation given. The maximum search space is 9.54E8. The initial explanations vastly reduce this search space, after two explanations are given, it is an average of 3.1E6 placements. This is why the user can teach the agent the rule after only seeing a small number of examples.  
Article
The ability to build intelligent agents is significantly constrained by the knowledge acquisition effort required. Many iterations by human experts and knowledge engineers are currently necessary to develop knowledge-based agents with acceptable performance. We have developed a novel approach, called Disciple, for building intelligent agents that relies on an interactive tutoring paradigm, rather than the traditional knowledge engineering paradigm. In the Disciple approach, an expert teaches an agent through five basic types of interactions. Such rich interaction is rare among machine learning systems, but is necessary to develop more powerful systems. These interactions, from the point of view of the expert, include: specifying knowledge to the agent; giving the agent a concrete problem and its solution that the agent is to learn a general rule for; validating analogical problems and solutions proposed by the agent; explaining to the agent reasons for the validation; and being guide...
 
Article
This paper reviews models and theoretical frameworks of collaborative awareness in the use of real-time groupware systems. The review is used to motivate and guide an investigation of distortion-oriented mechanisms for supporting collaborators' fluid and dynamic awareness requirements. We describe our development and evaluation of Dome, a distortion-oriented multi-user editor. Although we designed Dome to provide a realistic and useful platform for the investigation of awareness concepts, our evaluation revealed major flaws in its support for distortion-oriented awareness. We analyse the cause of these errors, some of which have been undetected in prior work, and provide precise formulations that will overcome them. Keywords: Groupware, collaborative workspace awareness, distortion-oriented visualisation 1 Introduction When working with others on physical media such as white-boards and desktops, collaborators maintain a continual awareness of their colleagues. This awarenes...
 
Collaboration widgets. Three users, bogdan (1), chris (2), and boi (3), collaborate over a chat bean and also post notes. User chris can see in his radar view (4) a view of the bean, the notes, telepointers, and viewing areas of all the users.
The medical diagnosis support application as used in the DISCIPLE desktop. The doctor receives an image from a remote microscope and selects a region of interest (1), segments the image (2), selects the cell kernel to extract (3), and searches the database for similar cells (4). Candidates are ranked on similarity.
Article
This article presents the design and implementation of a user interface for DISCIPLE, a platform-independent telecollaboration framework. DISCIPLE supports sharing of Java components that are imported into the shared workspace at run-time and can be interconnected into more complex components. Asaresult,run-timeinterconnectionofvariouscomponentsallowsusertailoring of the human--computer interface. Software architecture for customization of both a group-level and application-level interfaces is presented, with interface components that are loadable on demand. The architecture integrates the sensory modalities of speech, sight, andtouch.Insteadofimposingone "right" solutionontousers,theframework lets users tailor the user interface that best suits their needs. Finally, laboratory experience with DISCIPLE tested on a variety of applications with the framework is discussed along with future research directions
 
Article
This paper offers a set of goals for user interface development and then scenarios of future developments. The applications include home control, hypermedia, office automation, digital photography, collaborative meeting/classrooms, public access, professional workstations, and medical record-keeping. Also, predictions are made for some of the underlying technologies such as User Interface Management Systems, remote control, flexible search, display devices, and touchscreens. INTRODUCTION It is dangerous, but necessary, to dream about the future. Dangerous because misguided dreams mislead designers, necessary because without vision navigation is difficult. Without dreams we risk stagnation, and lose the chance to make a better world. This biased and partial portrait of the future is offered to guide designers of future interactive systems. It is organized topdown, from goals to applications to software/hardware. Planning for the future is never easy, but when innovation is the propelli...
 
Article
As handheld devices become ubiquitous and the tasks performed become multipurpose in nature, efficient data entry techniques are necessary. This research evaluated several speech-based text entry solutions for handheld devices using server-based speech recognition. Because server-based solutions introduce network delays, an analysis of the relationship among network delays, number of recognition errors, how fast users can correct errors, and overall data entry rates was performed. The analysis and empirical results confirm the importance of minimizing recognition errors. This suggests that a server-based approach that makes more computing resources available may prove effective. Results from two empirical studies are presented. The first compares two error correction mechanisms: a multitap and soft keyboard solution. The second employs a longitudinal investigation of the effects of experience on text entry rates. Users attained an effective mean text entry rate as high as 25.3 words per min, which is higher than or comparable to data entry rates reported for other input techniques for handheld devices. The results of this research have implications for researchers and designers of automatic speech recognition systems and mobile devices. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
 
Article
In this article, ethnographic fieldwork is discussed as a research technique for user-centered design in industry. The original meaning of fieldwork in ethnography is considered, and how ethnographically inspired fieldwork can enrich research and data gathering in a participatory design setting are discussed. The ethnographer in his or her field seeks to "go native." But in an industrial setting, there is neither time nor resources for prolonged engagement with users. Is there a "quick and dirty" version of going native? Five cases of video-based research techniques are presented as examples of a participant observation research strategy, and means of moving beyond observation are discussed. The ethnographer seeks to understand the world as it is. The designer wants to change the world through introducing new products. Is there a way to study the changes to come, of involving users in design in their own work context? In this article, design-in-context is introduced through 2 cases of user involvement.
 
Article
As Web-based interactive 3D graphics (Web 3D), popularly referred to as Virtual Reality, continue to become more affordable, research and development groups in various fields have been adopting Web 3D technology. In addition to simulation of 3D content, the ability to instantly display alternative looks has been recognized as an innovative way to improve communication in such fields as product design, architecture, and e-commerce. Despite substantial adoption of Web 3D, how and how much the technology benefits target users as well as the providers who choose to adapt the Web 3D technology are not well understood. Previous research has established that interactive 3D graphics provide users with unique human–computer interaction (HCI). However, little is known about how users experience the Web D graphics technology and how user–system interaction contributes to system usability. The purpose of this study is to build new knowledge of the user experience with interactive-3D graphics systems used for product demonstration. By testing the impact of the technology on the user–system interaction and usability and comparing this impact with that of conventional two-dimensional (2D) graphics, this study tries to better understand the Web 3D technology from an interdisciplinary view of technology acceptance, sense of presence, and HCI. The study investigated how system usability is affected by HCI in the context of a furniture-style preference survey. The results of the study display the clear advantage for Web 3D for usability and show that perceived usefulness and sense of presence both mediate the effect of the technology treatment on the usability outcomes. The contribution of this study is that it includes empirical data to show how Web 3D benefits users when adopted in the context of a product demonstration and how the advantage is obtained through the user's interaction with the Web 3D technology.
 
Article
This article proposes a 3-dimensional (3D) vision-based ambient user interface as an interaction metaphor that exploits a user's personal space and its dynamic gestures. In human-computer interaction, to provide natural interactions with a system, a user interface should not be a bulky or complicated device. In this regard, the proposed ambient user interface utilizes an invisible personal space to remove cumbersome devices where the invisible personal space is virtually augmented through exploiting 3D vision techniques. For natural interactions with the user's dynamic gestures, the user of interest is extracted from the image sequences by the proposed user segmentation method. This method can retrieve 3D information from the segmented user image through 3D vision techniques and a multiview camera. With the retrieved 3D information of the user, a set of 3D boxes (SpaceSensor) can be constructed and augmented around the user; then the user can interact with the system by touching the augmented SpaceSensor. In the user's dynamic gesture tracking, the computational complexity of SpaceSensor is relatively lower than that of conventional 2-dimensional vision-based gesture tracking techniques, because the touched positions of SpaceSensor are tracked. According to the experimental results, the proposed ambient user interface can be applied to various systems that require real-time user's dynamic gestures for their interactions both in real and virtual environments.
 
Article
User interfaces of current 3D and virtual reality environments require highly interactive input/output (I/O) techniques and appropriate input devices, providing users with natural and intuitive ways of interacting. This paper presents an interaction model, some techniques, and some ways of using novel input devices for 3D user interfaces. The interaction model is based on a tool‐object syntax, where the interaction structure syntactically simulates an action sequence typical of a human's everyday life: One picks up a tool and then uses it on an object. Instead of using a conventional mouse, actions are input through two novel input devices, a hand‐ and a force‐input device. The devices can be used simultaneously or in sequence, and the information they convey can be processed in a combined or in an independent way by the system. The use of a hand‐input device allows the recognition of static poses and dynamic gestures performed by a user's hand. Hand gestures are used for selecting, or acting as, tools and for manipulating graphical objects. A system for teaching and recognizing dynamic gestures, and for providing graphical feedback for them, is described.
 
Article
This study aimed at determining the user preferences and satisfaction concerning three-dimensional product representations in business-to-consumer electronic commerce. An experiment was designed and conducted on 20 college-age electronic shoppers to determine the user preference and satisfaction issues concerning two-dimensional (2D), three-dimensional low-interaction (3DL), and three-dimensional high-interaction (3DH) product representations. A valid and reliable survey with 0.89 Cronbach's alpha internal reliability coefficient was presented to participants after they completed tasks on each product representation type. Results indicated that participants found the 3D representations (both low and high interaction) more detailed, easier and more fun to use, more accurate, and carrying more information than 2D representations. It was concluded that 3D representations in general resulted in higher satisfaction for the shoppers. Future studies can be conducted to determine the business aspects of different product representations as well as human information visualization and processing issues relating to product representations in electronic commerce.
 
Environment layout and locations of target objects. Dots represent spatial locations used in hypertext displays.  
Mean Subjective Ratings of Experience in Four Navigation Fidelity Conditions Navigation Fidelity
Example of HTML node links used in Web 9-45°. Vertical arrows indicate forward or backward motion (up or down arrow button presses). Horizontal arrows indicate rotating views in 45° increments (right or left arrow button presses). Numbers represent node number. Capital letters represent the direction faced at that node.  
Screen shot of the Web 9-45° environment in black and white, showing the perspective view in Store 3 at node 8E.  
Sketch map data for within-store and between-store mean angular error (degrees) and 95% confidence intervals for navigation fidelity conditions.  
Article
To assess its usefulness as a Web navigation-aiding metaphor, a virtual Euclidean space was created that participants (N = 96) navigated to find information in a Web shopping environment. Acquisition of configural-survey 3-dimensional (3D) spatial knowledge of the environment, measured with pointing and sketch map tasks, was compared using perspective displays of virtual environments created using Hypertext Markup Language (HTML) versus a 3D graphics engine. HTML navigation fidelity was manipulated by varying the turn angles and the number of viewpoints per store. Lower navigation fidelity reduced configural knowledge acquisition, but HTML store environments using 45-turn angles and 9 viewpoints per store were not reliably different from the 3D virtual environment generated by a graphics engine with optical flow. Target object location (within-store, between-store) also had a significant effect. The results indicate that HTML could be used to develop virtual Web shopping environments using discrete perspective displays. Implications for Web shopping interface design are discussed.
 
Environment layout and locations of target objects. Note. Dots represent viewpoint locations used in hypertext displays. Top, bottom-left, and bottom-right layouts were used in the hallways, linear, and clustered conditions, respectively. A = armchair; C = couch; N = nightstand; CM = copy machine; SR = stereo; T = TV; F = refrigerator; SV = stove; W = washing machine.  
Screenshot in Store 3 environment in black and white. Note. The map menu inset used for between-room teleportation shown in the upper right-hand corner was present only in Experiment 2. The shaded room indicated the participant's current location, and it was colored a bright yellow.  
Sketch map data for within-store and between-store mean angular error (degrees) and 95% confidence intervals for hallway versus no hallway (linear, clustered) conditions in Experiment 1.  
Pointing data for within-store and between-store mean angular error (degrees) and 95% confidence intervals for hallway versus no hallway (linear, clustered) conditions in Experiment 1.  
Article
Getting lost within Internet applications has been addressed with limited success by treating hypertext navigation as analogous to spatial navigation. One alternative for shopping-specific interfaces is to create discrete virtual three-dimensional (3D) Euclidian spaces for web navigation. Equivalent configural spatial knowledge acquisition was obtained from searches in discrete HTML Euclidian environments and comparable desktop 3D virtual environments (Couture, Colle, & Reid, 200513. Couture , J. H. , Colle , H. A. and Reid , G. B. 2005. Navigation fidelity in 3D perspective displays for web-based shopping: From nodes to views. International Journal of Human-Computer Interaction, 19: 181–200. [Taylor & Francis Online], [Web of Science ®]View all references, International Journal of Human–Computer Interaction). However, between-store spatial knowledge was not optimal for both discrete HTML and continuous desktop virtual environments. Also, walking longer distances between stores is undesirable. These issues are addressed with two design options. In Experiment 1, better between-store spatial knowledge was acquired in linear and clustered arrangements of adjacent stores than with hallway travel between stores. In Experiment 2, map menu teleportation, selecting a store teleportation destination from a map menu, did not spatially disorient participants. Design implications for several domains were discussed.
 
Article
This study examines effects of the most common cause of blindness in persons over the age of 55 in the United States, age-related macular degeneration (AMD), on the performance of older adults when completing a simple computer-based task. Older users with normal vision (n = 6) and with AMD (n = 6) performed a series of drag-and-drop tasks that incorporated a variety of different feedback modalities. The user groups were equivalent with respect to traditional visual function parameters (i.e., visual acuity, contrast sensitivity, and color vision) and measured subject cofactors, aside from the presence or absence of AMD (i.e., drusen and retinal pigment epithelial mottling). Task performance was assessed with measures of time (trial time and feedback exposure time) and accuracy (error frequency). Results indicate that users with AMD exhibited decreased performance with respect to required feedback exposure time, total trial time, and errors committed. Some nonvisual and multimodal feedback forms show potential as solutions for enhanced performance, for those with AMD as well as for visually healthy older adults.
 
Article
This study aimed to compare the efficacy of face-to-face and online education seminars in the professional training of psychology majors and in promoting the development of social capital. Forty-four university students, balanced by gender, age, and academic achievement were divided in two groups, online and face to face, taught by the same teacher. Individual learning scales were administered and students were tested on group processes tasks to measure professional skills acquisition. A follow-up interview 9 months after the end of the seminar was undertaken to assess whether social bonds, formed during the seminars, had lasted over time. An analysis of variance and Mann-Whitney test were used to analyze the data. Results show that students of both groups increased their academic knowledge and social capital, but Computer Supported Collaborative Learning students acquired more group observation skills.
 
A popular format being widely used (http://www8.org/w8-papers/1c-xml/formsheets/formsheets.html)
A typical reading flow from the first survey
A typical reading flow from the second survey
Article
This article explores user reading activities and user preferences in the formats of Web-based academic articles by using the data from 2 online surveys. Researchers use the Web as a resource for academic articles. Despite this popular use, no generally agreed format exists on the Web. The Web environments of distributed users encourage the use of online remote evaluation. We applied an e-mail-based survey and a Web-based survey to the evaluation of some concepts for Web-based academic articles. The participants of the surveys were researchers in information technology and related areas. Our survey results show that readers take an overview of a Web-based academic article from the screen, print it out, and then read the printed article. The results also show that the formats employed by most of the Web sites for academic articles are against readers' preferences. The simple 2-frame format among the 5 given formats was most preferred by 47% of our respondents, but the cascaded page-windows format was regarded as the worst by 65% because of its high visual complexity on the screen. An interesting result is that 26% of the respondents regarded the paperlike format as the worst, but this format is widely used for Web-based articles. In addition, the importance of interactive examples embedded in a Web-based questionnaire was revealed from the 2 consecutive surveys. Details are discussed in this article. In the online remote surveys, the issues of Web-based academic articles were successfully addressed. The methods used in the surveys would be useful for usability tests of various concepts of other Web genres at an early design or redesign stage.
 
Article
The Virtual Academy is an educational model based on multiage teams of students and adults working through the Internet to build and use virtual worlds for educational purposes. These collaborations are mediated by a range of tools ranging from electronic mail to hypermedia and video links, and result in the creation of simulation‐based role‐playing adventure games within the ExploreNet software environment ExploreNet is an Internet‐based multimedia, multiuser domain constructed specifically for educational experimentation.This article describes the Virtual Academy Model, the ExploreNet software system, and an experiment conducted in the spring of 1995. The article describes the evolution of features of ExploreNet's user interface and their relevance to collaborative work by children.
 
Article
A threshold level for acceptable load on the musculoskeletal system of the neck and shoulder regions was explored by studying comparable groups of female workers with different development of musculoskeletal sick leave in these areas. The load on the neck and shoulder was assessed by recording electromyography (EMG) from m. trapezius (descending part). The quantitative analysis of the trapezius load was carried out by calculating the number and total duration of periods below 5% MVC (Maximum Voluntary Contraction), 8% MVC, and 10% MVC. To relate acceptable musculoskeletal load to health criteria such as acceptable limits for development of musculoskeletal illness in a group of workers, the incidence of musculoskeletal illness for the comparable groups was also compared with a control group of female workers without a continuous work load. Two groups of workers had a development of musculoskeletal sick leave, which was approximately the same as the incidence of such illness for the control group. The trapezius load for these groups was below 5% MVC for about 40% of the working time. By comparing the groups of workers with different development of musculoskeletal sick leave, the trapezius load differed only for load levels below 5% MVC; increasing duration of load levels below 5% MVC was associated with lower incidence of musculoskeletal sick‐leave. The results indicated that trapezius load below 5% MVC was important to reduce the incidence of load‐related musculoskeletal illness.
 
Article
This study was designed to determine the acceptable mixture level of key and speech inputs in a bimodal interface in which users were permitted to use both key and speech input systems. The mixture level was a controlled experimental variable. Five mixture levels were used: 0%, 25%, 50%, 75%, and 100%. The experimental task was to edit a document. The 0% mixture level meant that the participant performed an editing task using only the keyboard. At the 100% mixture level, the participant performed an editing task using only speech input. After each experimental condition had been tested, the participants' mental workload was also measured using the National Aeronautics and Space Administration-Task Load Index. The results suggest that the mixture level between 25% and 50% was acceptable in view of both the completion time and workload.
 
Article
As mobile TV is becoming increasingly popular, this study examines the factors affecting consumers' intentions to use and adopt DMB. By integrating a motivational perspective into the technology acceptance model (TAM), this study examines the socioeconomic determinants of DMB adopters and nonadopters in South Korea. Perceived availability and perceived quality are proposed as new constructs that reflect DMB-specific features. The empirical results overall support a modified TAM in explaining consumers' behavioral intentions to use/adopt DMB. In particular, the results of structural equation modeling suggest that perceived availability is positively associated with perceived benefit and the attitude toward DMB. In addition, the results suggest that adopters and nonadopters of DMB perceive its value differently, which implies how to promote the diffusion of DMB to nonadopters more effectively. Implications of this study are important for both researchers and practitioners.
 
Article
Existing research on user acceptance of mobile commerce has found that technological perceptions—such as perceived usefulness, perceived ease of use, and perceived compatibility—had significant effects on user behavior. However, the effects of personality traits have seldom been examined. The purpose of this research is to examine the effects of five personality traits of extraversion, agreeableness, openness to experience, conscientiousness, and neuroticism on user adoption of mobile commerce. Partial least squares was employed to conduct data analysis. The results show that extraversion has a strong effect on trust, whereas neuroticism has significantly negative effects on trust and perceived usefulness, both of which determine user intention to adopt mobile commerce.
 
Article
With the proliferation of online social networks, understanding how and why individuals adopt and use online social networks can help managers and marketers to design better methods and approaches towards engaging their users. The purpose of this study is to investigate the determinants of user acceptance of online social networks, with particular attention given to the effects of social influence. A research model was developed by incorporating two variables of social influence, subjective norm and critical mass, into an enhanced version of the Technology Acceptance Model (TAM), specifically to address issues related to online social networks. The model was empirically evaluated using survey data collected from 269 subjects about their perceptions of online social networks. The results reveal that both subjective norm and critical mass significantly affect perceived usefulness which further affects users' usage intention, and perceived ease of use affects the usage intention indirectly through perceived usefulness. The implications of this study upon theory and practice are discussed.
 
a.  
Article
Information and communication technology (ICT) acceptance and use is a prolific research stream in the information systems field. Yet studies on attitude have gone through ups and downs yielding inconsistent and inconclusive findings on attitude's role and impact. This article provides clear definitions of two different types of attitudes and details their relationships to each other and to technology use intention. Empirical data confirm the following: (a) At a theoretical level, attitude toward using ITC as a behavior (ATB) is a better predictor of behavioral intention (BI) than attitude toward ICT as an object (ATO) or ICT; ATO has a positive influence on ATB; and ATO's effect on BI is fully mediated by ATB. (b) Attitudes toward a previous version of the ICT and its use have significant impacts on the current attitudes. (c) At the operational level, considering only one aspect of the attitude constructs will lead to different results of the roles of attitudes on intention.
 
Proposed conceptual model.  
Proposed structural equation model.  
Results of Confirmatory Factor Analysis of the Theoretical Measurement Model
Article
The roles that users' individual and organizational characteristics play in technology acceptance were examined. Perceived work group characteristics was considered an organizational characteristic; attitude toward change and job stress were considered individual characteristics. User satisfaction with system characteristics was considered a consequence of technology acceptance. Data were collected from a sample of 236 Korean expatriates in information technology (IT) industries who were assigned to work in the United States. Perceived work group characteristics, attitude toward change, and job stress were related to one of the technology acceptance variables, perceived ease of use of the IT system. Ease of use was, in turn, related to perceived usefulness of the IT system, the other technology acceptance variable. Both perceived ease of use and usefulness were related to user satisfaction.
 
Article
The improvement of digital document technologies is changing our document browsing style. We browse a lot of documents in a short time, jumping from one to another by following the hyperlinks. This makes document management difficult; we sometimes feel it is difficult to keep track of all of the information. To overcome this problem, this article proposes a novel method that uses the user's eye movement to create passive traces of document comprehension for digital documents. The eye gaze traces so generated become metadata of the document; they can be used in the next search, document browsing, and zooming. A prototype system that works with a gaze tracking system is developed. Two experiments are conducted to evaluate the usefulness of eye gaze traces in digital document browsing. The first experiment examines the validity of trace generation, where generated eye gaze traces are compared with the ‘participants’ self-judgment of reading. In the second experiment, participants browse a set of documents to gather information, where the ‘participants’ reading behavior with the eye gaze trace and the efficiency of keyword search is studied. The results confirm that EyePrint is the answer to keeping track of digital documents.
 
Sample inbox with voicemail messages.  
Sample mobile assistant conversation.  
Average functional composition per call.
Number of voice mail messages delivered by month (through January 12th).
Article
The advent of mobile devices and the wireless Internet is having a profound impact on the way people communicate, as well as on the user interaction paradigms used to access information that was traditionally accessible only through visual interfaces. Applications for mobile devices entail the integration of various data sources optimized for delivery to limited hardware resources and intermittently connected devices through wireless networks. Although telephone interfaces arise as one of the most prominent pervasive applications, they present interaction challenges such as the augmentation of speech recognition through natural language (NL) understanding and high-quality text-to-speech conversion. This article presents an experience in building an automated assistant that is natural to use and could become an alternative to a human assistant. The Mobile Assistant (MA) can read e-mail messages, book appointments, take phone messages, and provide access to personal-organizer information. Key components are a conversational interface, enterprise integration, and notifications tailored to user preferences. The focus of the research has been on supporting the pressing communication needs of mobile workers and overcoming technological hurdles such as achieving high accuracy speech recognition in noisy environments, NL understanding, and optimal message presentation on a variety of devices and modalities. The article outlines findings from the 2 broad field trials and lessons learned regarding the support of mobile workers with pervasive computing devices and emerging technologies.
 
Article
Every year, government agencies, financial institutions, and other businesses spend millions of dollars gathering and publishing statistical data, presumably intended for use by other organizations in planning. From the point of view of the end user, these data are external statistical data (ESD) because they are provided by external sources over which the end user has little control. Typical sources of ESD include national statistical agencies, such as the Australian Bureau of Statistics (ABS), regional information services, and various state and national government departments.
 
Article
This article proposes and describes a visitor-oriented perspective emphasizing the unique needs of visitors of digital environments in contrast to the user-oriented perspective that emphasizes the needs of users. To do so, the term accommodation is introduced in a technical sense and given a brief explanation. Results are also reported from 3 explorative studies of desktop virtual reality environments. In these studies, the visitor-oriented perspective was adopted and allowed for analyzing how participants perceived the environments as places rather than artifacts for use. In comparison to a web site, it was found that even a rudimentary virtual reality environment can have a positive impact on visitor regard for information content. Implementing teleports increased the efficiency of 1 test environment, but it was not found to have a positive effect on user attitudes to the environment. Many participants felt that the environments were sterile. Another common complaint was about the amount of walking required in the first environment. Five suggestions are given for building desktop virtual reality environments that are better received by visitors. In closing, the visitor-oriented perspective presented here is briefly discussed in relation to Winograd and Taber's (1997) writings on software inhabitants.
 
Article
This study looks at the performance model of mouse movement from the following three viewpoints: (a) effects of the direction of movement on the performance model, (b) optimal formula to define the size of targets in the performance model, and (c) comparison of fit to the pointing time among five performance models. As a result, it was shown that the fit to the experimental data did not differ among four conditions of direction of movement The contribution of the performance model was found to be the highest when the square of the area of a target is used as the size of a target. Moreover, the performance model based on the multiple‐regression analysis was better than that based on Fitts's law.
 
Article
This study examined performance effects of using electronic performance monitoring (EPM) and feedback to induce compliance with speed and accuracy standards in a data entry task. The study focused on subjects who had difficulty meeting a preestablished data entry speed standard. Subjects performed a data‐entry task for 3 days. On the 1st (baseline) day, no performance standards were imposed, and all subjects were instructed to work at their normal speed and accuracy levels. For the 2nd and 3rd days of the experiment, subjects were assigned at random to one of two groups. In an experimental group, EPM and feedback were used to induce compliance with preestablished speed and accuracy standards. In a control group, subjects were unaware of EPM and received no feedback; they were instructed to continue working at their normal speed and accuracy levels. The introduction of EPM work management in the experimental group led to significant increases in data‐entry speed that were accompanied by significant increases in data‐entry errors. In addition, data‐entry errors produced by experimental subjects increased significantly over time during the workdays in which EPM work management was employed. These effects are discussed in terms of relevant research on goal setting and feedback utilization. The results suggest that when performance standards and feedback that emphasize speed more than accuracy are applied in EPM‐managed work settings, speed increments may be offset by decrements in work quality.
 
Article
Comprehensive and computational models of human performance have both scientific and practical importance to human–machine system design and human-centered computing. This article describes QN-ACES, a cognitive architecture that aims to integrate two complementary classes of cognitive architectures: Queueing network (QN) mathematical architecture and ACT–R, CAPS, EPIC, and Soar (ACES) symbolic architectures. QN-ACES represents the fourth major step along the QN architecture development for theoretical and methodological unification in cognitive and human–computer interaction modeling. The first three steps—QN architecture for response time, QN-RMD (Reflected Multidimensional Diffusions) for response time, response accuracy, and mental architecture, and QN-MHP (Model Human Processor) for mathematical analysis and real time simulation of procedural tasks—are summarized first, followed by a discussion of the rationale, importance and specific research issues of QN-ACES.
 
Article
The integration of brain monitoring into the man-machine interface holds great promise for real-time assessment of operator status and intelligent allocation of tasks between machines and humans. This article presents an integrated hardware and software solution for acquisition and real-time analysis of the electroencephalogram (EEG) to monitor indexes of alertness, cognition, and memory. Three experimental paradigms were evaluated in a total of 45 participants to identify EEG indexes associated with changes in cognitive workload: the Warship Commander Task (WCT), a simulated navy command and control environment that allowed workload levels to be systematically manipulated; a cognitive task with three levels of difficulty and consistent sensory inputs and motor outputs; and a multisession image learning and recognition memory test. Across tasks and participants, specific changes in the EEG were identified that were reliably associated with levels of cognitive workload. The EEG indexes were also shown to change as a function of training on the WCT and the learning and memory task. Future applications of the system to augment cognition in military and industrial environments are discussed.
 
Article
Knowledge elidtation is an expensive and vital part in the construction of knowledge‐based systems. This paper indicates that the acquisition of procedural knowledge can significantly be improved, depending on the tasks (interpretation, debugging, or diagnosis) for which the knowledge is elicited; the method of knowledge elicitation (protocol, interview, induction, or repertory grid), and the number of experts (from one to six) from whom knowledge is elicited. On average, for all conditions the percentage of acquired procedural knowledge increased by two‐fold from using one to six experts. The optimal cost‐benefit utility may be achieved by using three experts for knowledge elicitation.
 
Article
This study describes three experiments in which the influence of different force-field radii on efficiency and satisfaction is tested within a target acquisition task. The first two experiments tested four radii, starting after 0%, 30%, 60%, or 80% of the total distance of a cursor movement was covered. In the first experiment, the force field with the largest radius was found to be the least satisfying, whereas the force field starting after 60% was the most satisfying. In the second experiment, however, the force field with the largest radius was found to be the most efficient. The third experiment presented two or more targets simultaneously and included a prediction algorithm, predicting a user's intended target. The force field starting after 30% of the path was found to be the least efficient and the least satisfying. The no-force condition was most efficient but was not rated higher than the two smallest fields.
 
Article
The rapid growth of data in large databases, such as text databases and scientific databases, requires efficient computer methods for automating analyses of the data with the goal of acquiring knowledges or making discoveries. Because the analyses of data are generally so expensive, most parts in databases remains as raw, unanalyzed primary data. Technology from machine learning (ML) will offer efficient tools for the intelligent analyses of the data using generalization ability. Generalization is an important ability specific to inductive learning that will predict unseen data with high accuracy based on learned concepts from training examples. In this article, we apply ML to text-database analyses and knowledge acquisitions from text databases. We propose a completely new approach to the problem of text classification and extracting keywords by using ML techniques. We introduce a class of representations for classifying text data based on decision trees; (i.e., decision trees over attributes on strings) and present an algorithm for learning them inductively. Our algorithm has the following features: It does not need any natural language processing technique and it is robust for noisy data. We show that our learning algorithm can be used for automatic extraction of keywords for text retrieval and automatic text categorization. We also demonstrate some experimental results using our algorithm on the problem of classifying bibliographic data and extracting keywords in order to show the effectiveness of our approach.
 
Article
A recently developed decision support tool provides a common information space to share information directly across numerous air traffic control facilities. This tool is unusual in that its displays can be used as boundary objects, which are entities in which decontextualized information is presented in the same form to all participants in the collaboration. Through an analysis of the results of 2 years of field tests, this article discusses the benefits of this arrangement, particularly in comparison to alternative concepts for collaborative work displays, and identifies key aspects for the design of boundary object displays.
 
Participants' ratings of their use of and association with information technology, N = 48 participants.
Constructs related to system characteristics.
Constructs related to the task or use context.
Constructs related to use experience.
Article
Whereas the concept of usability is predominantly defined analytically, people relate to systems through personal usability constructs. Based on 48 repertory-grid interviews, this study investigates how such personal constructs are affected by two factors crucial to the international development and uptake of systems: nationality (Chinese, Danish, or Indian) and stakeholder group (developer or user). We find no significant overall difference across nationalities, but further analyses suggest that conventional usability aspects such as ease of use and simplicity are prominent for Chinese and Danish but not Indian participants and that a distinction between work and leisure-related communication is central to Chinese and Indian but not Danish participants. For stakeholder groups, we find a significant overall difference between developers and users. Unlike developers, users associate ease of use with leisure and, conversely, difficulty in use with work-relatedness. Further, users perceive usefulness as related to frustration and separate from ease of use, whereas developers construe usefulness, fun, and ease of use as related. In construing usability, participants make use of several constructs that are not part of prevailing usability definitions, including usefulness, fun, and security.
 
Article
Two experiments are reported that examine the effects of menu organization and command naming on performance within and across computer command menus. The work on performance within menus extends prior work on information retrieval (IR) menus to computer command menus. We found that selection of computer commands conforms to the same laws that govern selection of IR categories and object names, with alphabetic organization leading to shorter search times in early trials when users knew the names of the commands. When users did not know the exact names of the commands, the functional organization led to shorter search times. More importantly, we found that the knowledge of the functional organization transferred from one application menu to another, thereby reducing search time in the menu of the second application.
 
Article
The Next Generation Air Transportation System (NextGen) will revolutionize the air traffic management system in the United States. NextGen will involve human operators interacting with new technologies in a complex system, making human factors and human–computer interaction considerations a major concern. The present study reports data from a human-in-the-loop simulation that evaluated pilot performance, workload, and situation awareness under one of three plausible NextGen concepts of operation. The concepts of operation differed with respect to the allocation of separation responsibility across human pilots and air traffic controllers (ATCs), and automation. Pilots were asked to employ trajectory-based operations to perform weather avoidance maneuvers, an interval management task, and a continuous descent approach. Depending on the concept being tested, they were also given the responsibility of separation assurance (Concept 1) or received conflict resolutions from an ATC (Concept 2) or automated system (Concept 3). Overall, pilot performance on the various flight tasks was worse in Concept 3 than in Concepts 1 and 2. Although pilot workload did not differ across the three concepts, pilot situation awareness was highest in Concept 1, in which the pilots were given the most responsibilities. These findings suggest that keeping pilots engaged in separation assurance tasks may be preferable to having them rely on automation alone.
 
Article
Subjects practiced drawing a figure on a computer screen by means of two interaction styles: Command codes and direct manipulation. These two interaction styles demanded different cognitive resources of the user and different times to perform the task. After practice, subjects performed multiple trials in three experimental conditions: in a time‐limit condition, with office noise, and in a neutral working condition. The drawing task was performed concurrently with one of three secondary tasks, each tapping different resources. In Experiment 1, subjects were divided into two equal size groups. Each group performed the task with only one of the two learned interaction styles. Secondary and primary task performance indicated no difference in workload between the two interaction styles. Only at the most demanding secondary task did the use of command codes result in higher workload. In Experiment 2, subjects performed the drawing task in each trial using their preferred interaction style. Consistent individual preferences for the interaction styles and a flexible use of the styles according to working conditions emerged with improved performance.
 
Article
The timing involved in generating communicative actions and utterances in a face-to-face greeting interaction for application in robot–human and computer-generated (CG) character–human interaction support systems is analyzed by synthesis. First, an analysis of human greeting clarifies the average pause and the average time delay in the utterance to a communicative action. Then, a synthesis-based analysis is performed by using an embodied robot system. This analysis confirms that the variation in the pause and the lag in the utterance to communicative actions produce different communicative effects, for example, a lag of about 0.3 sec is desirable for a familiar greeting and a longer lag is appropriate for a polite greeting. In addition, the synthesis-based analysis performed on a CG character system confirms the timing control effects. These results demonstrate the importance of timing control in embodied interactions as well as the applicability of such interactions in advanced communications with robots and CG characters.
 
Top-cited authors
Marc Hassenzahl
  • Universität Siegen
Niels Ebbe Jacobsen
  • International Consumer Research & Testing Ltd, London, UK
Morten Hertzum
  • University of Copenhagen
Jan Håvard Skjetne
  • SINTEF Digital
Petter Bae Brandtzaeg
  • University of Oslo