As mobile robots become more common in shared public spaces, understanding how their movements affect pedestrian comfort has become a key challenge in human–robot interaction. Although prior research has investigated the effects of robot lateral distance and speed, findings have been inconsistent, with little attention paid to how these factors interact with pedestrians’ mobility states (e.g., walking vs. stopping). To address this gap, we conducted a virtual reality experiment where participants experienced 30 scenarios combining five lateral distances, three robot velocities, and two pedestrian states. Discomfort was measured using standardized questionnaires and real-time button presses. Results showed that discomfort increased at closer distances and higher speeds, with these effects amplified when pedestrians were walking. Discomfort was minimized when robots-maintained distances over 120 cm and moved slower than typical walking speed. This study offers new insights into how robot proxemics and pedestrian mobility jointly shape discomfort, informing proximity-aware navigation design.

External human–machine interfaces (eHMIs) are crucial for facilitating effective communication between autonomous vehicles (AVs) and vulnerable road users (VRUs). To design a user-centered eHMI, we identified pedestrians and motorcyclists as target users and specified eHMI usage scenarios accordingly. We aimed to investigate effective eHMI designs (position and message type) for the users in different usage scenarios through interviews and user testing. In the interview phase, 30 participants discussed their preferences for eHMI message types and positions for various scenarios. The user-testing phase involved 63 participants evaluating the visibility, interaction comfort, perceived safety, and workload of different eHMI positions (front windshield, door panel, grille, and rear windshield) and message types (guidance and informational) through virtual reality. Motorcyclists generally preferred informational messages and the rear windshield position, whereas pedestrians preferred the guidance messages and the front windshield and grille positions. These findings concurred with the interview results. Additionally, significant interaction effects were observed between the eHMI position and the usage scenario. In conclusion, motorcyclists and pedestrians exhibited different preferences for eHMI message types+ and positions. These position preferences depend on the usage scenario. This research highlights the importance of considering the target users for eHMIs, their needs, and their usage scenarios, offering valuable insights for the development of advanced eHMI systems.

Teleoperation technology has emerged as a solution to address safety hazards in high-risk environments. However, limitations in visual perception can often impede the accurate assessment of terrain features and obstacles. This study aimed to analyse the impact of AR interface design on distance perception during teleoperation, focusing on multi-view displays and AR visual cues. Distance estimation errors, task completion times, and workload were measured to identify designs that best support perception while minimizing effort. Results showed that a multi-view interface significantly improved distance perception, with the overhead-view condition yielding the most effective performance. Increasing the density of AR line cues further enhanced perception, although improvements diminished beyond a threshold. These findings highlight the importance of optimizing rather than maximizing visual cue density. Overall, the study provides fundamental guidance for designing AR-based teleoperation interfaces in high-risk domains such as construction, where accurate distance perception and reduced operator workload are critical.

This study addresses the challenge of ensuring pedestrian safety in shared spaces during human-robot interactions. As mobile robots become increasingly integrated into public environments, there is a need to better understand how pedestrians perceive robots in proximity. This research explores the effects of robot lateral distance, robot velocity, and pedestrian state on pedestrian perception, with a particular focus on proximity zones during human-robot interactions. Conducted in a virtual reality environment with a within-subject design, the study measured perceived danger through button presses and visualized proximity zones using contour density plots. Findings reveal that increasing lateral distance significantly decreases button press likelihood, particularly beyond 160 cm. Robot velocities of 1 mls and 1.5 mls showed no significant difference, suggesting pedestrians perceive them similarly due to their alignment with average walking speed. Proximity zones were consistently wider and denser on the left than the right, highlighting spatial asymmetry in perception. These results provide quantitative and visual insights for designing mobile robots in shared spaces. Future research should examine environmental and group dynamics and robot design to enhance safety and public acceptance in human-robot interactions.

This study investigates the influence of human-machine interface (HMI) design on passenger trust in autonomous electric vertical take-off and landing (eVTOL) vehicles. An immersive simulator-based experiment was conducted with 34 participants, exposing them to four HMI conditions: baseline, movement, hazard detection, and full information condition. As related measures of passenger trust, we collected self-reported measures including trust, perceived safety, perceived reliability, and intention to use. In addition, physiological measures including gaze behavior, electrodermal activity, and heart rate were collected. The results indicated that movement and hazard detection information improved passenger trust, suggesting that HMI design could play a crucial role in enhancing the acceptance of autonomous eVTOLs. In addition, gaze behavior showed a stronger relationship with self-reported trust than other physiological measures. The findings underscore the importance of HMI design in fostering passenger trust, which is critical to the success of urban air mobility.

Communicating effectively with autonomous vehicles requires contextualized visual and auditory cues to ensure clear message delivery. Evaluating the user experience involves assessing which types of information can be safely reacted to without additional monitoring and how it is presented. Validating the visual and auditory cues supports the driver’s course of action. This study investigates message types and preferred modalities of driver-to-driver communication via vehicle-to-everything (V2X) in advanced driver assistance systems technologies for autonomous and manual driving and proposes efficient ways to respond to event situations. Four modalities, including baseline and three message types with different information were proposed to investigate the information required by drivers. Results indicate that providing notifications during autonomous driving is more helpful and less workload-intensive than during manual driving. Most notifications were highly visible and easy to recognize. Although behavioral messages in both autonomous and manual driving enhance usability, providing advice and behavioral messages is safer for autonomous driving. Designing V2X notification information based on future events is vital because of its highly pragmatic nature.

The purpose of this article is to propose a View Sharing Augmented Reality (AR) interface aimed at improving situation awareness (SA) during military operations. Battlefield Augmented Reality System (BARS), a mobile AR system, supports real-time battlefield situation awareness (SA) for mission execution through collaborative information sharing. Video-based View Sharing AR interface that provides the perspective of team members located remotely can enhance team-level SA. However, instances have been identified where providing the perspective of team members moving in directions different from the user’s path can lead to user confusion and have a negative impact on mission execution. In this study, we investigate the influence on SA when presenting the perspective of team members with different path direction through a View Sharing AR interface and to examine the impact of visual AR cues supporting spatial awareness on SA improvement. The study was designed to experience the View Sharing AR interface in a virtual reality (VR) environment using the Unity3D game engine. The experiments involved performing tasks to suppress enemies with three different path direction variances in perspective provision and receiving support from four visual AR cues. SA was measured through SA Global Assessment Technique (SAGAT) and Performance measurement. The research findings indicate that differences in path direction negatively affected SA, with the lowest SA observed when the path difference was 90°. Furthermore, visual AR cues, when providing Tramline cues, demonstrated the highest SA, showing interaction effects with path direction differences.

Users often select different modalities in multimodal systems based on context and function. This study aimed to investigate the impact of context on users’ modality selection in a multimodal system. A modality selection task was presented through the developed multimodal system, where the task’s difficulty was controlled based on the number of syllables and touches. The experiments were examined in four usage contexts (baseline, watching, reading, and driving), and the selected modality, physical and mental effort, and satisfaction were measured. A regression model for predicting modality selection was established using binomial logistic regression. The results showed that voice usage increased in the order of baseline, watching, reading, and driving contexts. It was revealed that these changes were attributable to differences in physical and mental interaction efforts of modalities according to contexts. Our finding provides valuable insights into users’ modality selection in different contexts, which could inform the design of more efficient multimodal systems.

The purpose of this study was to explore the unit of information and the size of the unit for designing a voice user interface. Through two experiments, this study investigated what form the information (the unit of information) should take and what size of that (the size of unit) should be when people were provided information by voice interfaces. Participants were presented with a task to recall (OX quiz) by listening to and remembering information (based on an encyclopedia) provided by smart speakers. In Experiment 1, it was revealed that participants stored information in their memory span on a sentence-by-sentences basis to determine how much information they could remember. In Experiment 2, sentence-based information was presented in various sizes, and participants evaluated 17 information units consisting of up to nine words as their memory limit. This information unit-based voice interface design could help improve users’ memory performance and usability.

Four-wheel independent steering (4WIS) vehicles refer to vehicles designed to be able to move in multi-orientation by eliminating the mechanical linkage among the wheels. This study aims to evaluate and compare the usability of previously proposed 4WIS vehicle controllers. A usability test with 33 drivers was conducted to compare the five control interfaces (steering wheel buttons, touchscreen buttons, center console buttons, joystick, and paddle shifters). In order to identify what factors contributes to the usability of 4WIS control interfaces, we utilized a mixed-method approach that collects and analyzes both quantitative and qualitative data within the study. The quantitative results indicate that button-type interfaces shorten task completion time and reduce workload than joystick or paddle shifters. Qualitative analysis implies that touchscreen buttons reduce the perceived safety of drivers due to the lack of tactile feedback. Design recommendations for 4WIS control interfaces were provided from the usability testing results.

Enhancing the user experience of in-vehicle infotainment system (IVIS) GUIs has gained importance in the vehicle industry. However, there are no studies on the effects of animated transitions in an IVIS screen. We investigated the effects of animated transitions on the perceived duration, delay time, and satisfaction of IVISs. Forty participants divided into two groups (Slide and Fade) performed touch tasks to experience different transition effects and evaluate each condition. The transitions were manipulated considering transition type (NS, Split-R, Split-M), easing type (Ease-out, Ease-In), and interval time (0, 150, 300, 450, 600 ms). An analysis indicated that Split-R (fade-fade) in the Fade group and Split-M (fade-slide) in the Slide group best satisfied users. Post-interviews revealed that the interval time should not exceed 450 ms, while an appropriate interval (150 ms) is necessary to enhance the user’s visual perception and satisfaction. Our results may provide effective guidelines for designing animated transitions in IVIS.

The purpose of this study is to explore how trust in and the service quality of urban air mobility (UAM) relate to the user acceptance of UAM. We hypothesized that trust directly influences the attitude and intention to use UAM, while service quality factors affect its perceived usefulness and ease of use. A survey data of 450 respondents were analysed by using a partial least squares structural equation model. The results show that trust positively influences the intention to use UAM, and safety perception contributes the most to UAM’s trustworthiness. In addition, transport service quality factors (i.e., time-saving, availability, flight comfort, and perceived cost) significantly explained the perceived usefulness and/or ease of use. Path coefficients of the structural model indicate that trust has a greater impact on the user's attitude toward UAM than perceived usefulness. The results of this study contribute to increasing the early user adoption of UAM.

Accepted version

Because the use of handheld mobile phones while driving is considered dangerous behavior, mounted mobile phones have emerged as an alternative. This study compared use of mounted with handheld mobile phones while driving and investigated the impact of mounted mobile phones on driving behavior. The behavior of receiving and making calls, and reading/sending text messages using mobile phones mounted on windshields, dashboards, vents, and cupholders while driving was observed. It was found that mounted mobile phones have less distraction potential than handheld mobile phones; however, they can distract the driver to the same degree, depending on the mounting position. In conclusion, a key factor that determines the potential distraction level of a mounted mobile phone while driving is the mounting position. The hands-free law should consider the mounting position of the mobile phone, rather than focus exclusively on manual interaction.

This study aimed to investigate the effects of non-driving-related tasks (NDRTs) on takeover quality in the context of automated driving. Specifically, we examined the effects of three categories of NDRT attributes (i.e., physical, cognitive, and visual) on longitudinal and lateral driving measures when the drivers resumed control. We designed a driving simulator study where the participants experienced automated driving journeys and takeover situations. When the automated mode was activated, drivers engaged in one of the nine NDRTs. The results showed that the cognitive load of NDRTs had a significant negative correlation with both longitudinal and lateral control measures. However, the effects of two attributes in the physical category and one attribute in the visual category on driving performance did not show statistical significance. Overall, the findings indicated that the influence of cognitive attributes on takeover quality is more salient than that of the physical and visual attributes, which provides insights into the understanding of takeover situations to improve driving safety.

This study aims to investigate the effects of edge displays on smartphone usage in one-hand-only use scenarios and identify issues related to touch errors. Experiments were conducted by recreating typical usage environments to mimic the use of phones in cafeterias, homes, and mobile settings. A framework to analyze smartphone usage and human errors was developed. We collected data on the usage errors and use cases through a head-mounted camera donned by participants and a screen-recording application. The results showed that the number of incidents involving unintentional touching of screen edges for edge-screen smartphones is five times higher than that for typical flat smartphones. Moreover, the lying down position is more susceptible to errors for both types of smartphones. These results indicate the necessity of design strategies to reduce unrelated touching of screen edges and the importance of considering various body postures to elucidate a better understanding of smartphone usage.

The objective of this study was to investigate the touch area that can be comfortably reached by the thumb during one-handed smartphone interaction. To achieve the research objective, we introduced the concept of natural thumb position when designing a tapping task and conducted an user experiment. The independent variables were the target distance and direction from the natural thumb position, and the three dependent variables were the task performance, information throughput, and touch accuracy. The results showed that participants performed the task comfortably in the diagonal direction between the upper right and the lower left side of the screen. The task performance deteriorated as the target distance increased, especially at 45 mm or more. The touch accuracy was measured using X- and Y-coordinates data. Participants touched the left side of the target center, except near the proximal area of the hand. They also touched the points above the center of the target in the upper screen area and points below the center of the target in the lower screen area. The findings of this study provided insights for designing a smartphone touch interface considering the comfortable touch areas of one-handed interaction.

Smart functions in vehicles have led to an increase in the complexity of control interfaces. This study aims to develop a model for evaluating in-vehicle controller complexity and to investigate the relationship between complexity and task performance. A research framework consisting of three complexity dimensions (functional, behavioral, and structural dimensions) and controller-related variables was developed based on previous literature. A user experiment was conducted using 10 vehicles and 91 participants. A regression analysis was used to examine the relationship between the measurement variables and perceived controller complexity, and the results indicated correlations between them. An increase in functional dimension variables caused an increase in the perceived complexity level, while behavioral dimension variables are not a statistically significant predictor. Structural dimension variables showed different results depending on the characteristics of the variables. The results of the control task experiment showed a negative correlation between task performance and the perceived complexity level. In addition, satisfaction decreased with increasing levels of complexity. These results provide insights for managing in-vehicle controller complexity.

With the development of information and communication technologies, the younger generations as well as more mature generations accept and enjoy playing digital games. The game industry is rapidly g...

Despite enhancements in the visual complexity of in-vehicle information display in recent years, few studies have examined the effects of such increased complexity. We conducted this study with the following objectives: (1) to suggest a framework for predicting the perceived visual complexity (PVC) of in-vehicle information display; (2) to examine the effects of PVC on the visual behavior of human operators; (3) to investigate the relationship between preferences and PVC. A theoretical framework to evaluate PVC was developed, and a survey study was used to collect participants’ perceptions on visual complexity. A regression analysis was employed to find the relationship between each of three factors and PVC. Two of the factors—quantity and variety—showed a positive correlation with PVC, whereas the third factor, relation, exhibited a negative correlation. Visual search experiments were conducted to test the effects of PVC on the performance of visual search tasks and glance behavior. The results showed that the high level of PVC leads to more time-on-task and number of fixations. We also found that preference for in-vehicle information displays was inversely proportional to PVC. The results enable us to predict how human operators perceive visual complexity and explain the influence of PVC on human behavior.

A vehicle head-up display (HUD) has a semitransparent property that utilizes a method of projecting light onto the windshield. The semitransparent characteristic of the HUD generates continuous superimposition between the “HUD graphic” and “road environment events.” This study aims to determine the effects of HUD use on elderly driving. Two age groups (elderly, younger) performed tasks (speed monitoring, navigation) utilizing two types of display (HUD, head-down display) in two different circumstances (high superimposition level, low superimposition level). Subject performance was evaluated by having the subjects execute a secondary display task while performing a primary driving task with an eye-tracking task. In addition, the degree of driver visual distraction was verified through the measurement of display glance duration. The results showed that an increase in superimposition negatively affected driver glance duration independent of age. However, the use of HUD in low superimposition situations showed relative advantages with regard to display use independent of age. This study confirmed that the negative effects of HUD use need to be considered during the selection of HUD information and display location. In particular, this study verifies that special attention should be given to the negative effects of superimposition of text information for use by an elderly population.

The objective of this study is to examine the user’s adoption aspects of autonomous vehicle, as well as to investigate what factors drive people to trust an autonomous vehicle. A model explaining the impact of different factors on autonomous vehicles’ intention is developed based on the technology acceptance model and trust theory. A survey of 552 drivers was conducted and the results were analyzed using partial least squares. The results demonstrated that perceived usefulness and trust are major important determinants of intention to use autonomous vehicles. The results also show that three constructs—system transparency, technical competence, and situation management—have a positive effect on trust. The study identified that trust has a negative effect on perceived risk. Among the driving-related personality traits, locus of control has significant effects on behavioral intention, whereas sensation seeking did not. This study investigated that the developed model explains the factors that influence the acceptance of autonomous vehicle. The results of this study provide evidence on the importance of trust in the user’s acceptance of an autonomous vehicle.

"HCI for Elderly and Smart Vehicle Interaction." International Journal of Human-Computer Interaction, 31(10), pp. 633–634

Advancements in technology have spurred the development of new in-vehicle applications. Drivers are faced with different driving contexts due to an increase in the number of devices that provide a wealth of diverse information. However, such a scenario can cause drivers to become distracted. Therefore, research on how the presentation of visual information can affect drivers’ performance is important. In this study, an analysis of quantifiable measurements that affect drivers’ perception of visual complexity and visual search performance was conducted. A questionnaire was administered to assess subjective perception of visual complexity, and a user experiment using eye tracking was designed to explore participants’ visual search performance. The results of subjective visual complexity perception and visual search performance suggested that some objective measurement variables were significantly related only to perceived visual complexity, whereas others affected both subjective and behavioral measurements. Thus it is possible to predict which quantifiable measurement variables affect subjective perception of visual complexity and which affect visual search performance. Therefore, this study allows understanding and explaining of perception of visual complexity by quantifiable measurements and the different ways by which these measurements affect visual search performance.

The number of global smartphone users is rapidly increasing. However, the proportion of elderly persons using smartphones is lower than that of other age groups because they feel it is difficult to use touch screens. There have only been a few studies about usability and elderly smartphone users or designs for them. Based on this background, we studied the pointing action of elderly users, which is a basic skill required to use touch screens on smartphones. We reviewed previous works to determine specific research methods and categorized them into three groups: (a) effect of target size and spacing on touch screen pointing performance, (b) effect of age on pointing performance, and (c) feedback of touch screens. To investigate the touch screen pointing performance of elderly, we conducted two experiments. In the first experiment, 3 target sizes (5 mm, 8 mm, and 12 mm) and 2 target spacings (1 mm, 3 mm) were evaluated. Adding to that, we analyzed whether touch screen pointing performance is dependent on the location of the target. In the second experiment, 3 types of feedback (auditory, tactile, and audiotactile) were evaluated. The results show that (a) pointing performance of elderly was significantly influenced by size, spacing, and location of target, and (b) the performance was higher in audiotactile feedback condition. We expected that these results can contribute to the design of smartphone applications for elderly users.

This research focuses on identifying continuous usage intentions before and after the product adoption phase. A theoretical model was developed, specifying continuous usage intentions and user behavior throughout the product adoption life cycle. The proposed model considers users' characteristics, product quality, sociocultural factors, and continuous usage intention factors, which were obtained from previous studies related to technology acceptance models and continuous usage. The relationship between these factors was analyzed, hypotheses tests to verify the relationships were conducted, and the proposed model was confirmed. Quantitative data were collected using a survey targeted at smart phone users. Data analysis verified the continuous usage model using structural equation modeling. The results from before and after the product adoption phase showed that previous usage experience affects users' characteristics, perceived usefulness, and social factors. The data proved causality between user satisfaction, attachment, commitment, and continuous usage intention after the adoption phase. The relationship between the factors and the model itself was verified statistically, providing insight into the adoption–diffusion–usage perspective with regard to the interaction between user and high-tech product.

Through the rapid spread of smartphones, users have access to many types of applications similar to those on desktop computer systems. Smartphone applications using augmented reality (AR) technology make use of users' location information. As AR applications will require new evaluation methods, improved usability and user convenience should be developed. The purpose of the current study is to develop usability principles for the development and evaluation of smartphone applications using AR technology. We develop usability principles for smartphone AR applications by analyzing existing research about heuristic evaluation methods, design principles for AR systems, guidelines for handheld mobile device interfaces, and usability principles for the tangible user interface. We conducted a heuristic evaluation for three popularly used smartphone AR applications to identify usability problems. We suggested new design guidelines to solve the identified problems. Then, we developed an improved AR application prototype of an Android-based smartphone, which later was conducted a usability testing to validate the effects of usability principles.

The implementation of haptic interfaces in vehicles has important safety and flexibility implications for lessening visual and auditory overload during driving. The present study aims to design and evaluate haptic interfaces with vehicle seats. Three experiments were conducted by testing a haptic seat in a simulator with a total of 20 participants. The first experiment measured reaction time, subjective satisfaction, and subject workloads of the haptic, visual, and auditory displays for the four signals primarily used by vehicle navigation systems. The second experiment measured reaction time, subjective satisfaction, and subjective workloads of the haptic, auditory, and multimodal (haptic + auditory) displays for the ringing signal used by in-vehicle Bluetooth hands-free systems. The third experiment measured drivers' subjective awareness, urgency, usefulness, and disturbance levels at various vibration intensities and positions for a haptic warning signal used by a driver drowsiness warning system. The results indicated that haptic seat interfaces performed better than visual and auditory interfaces, but the unfamiliarity of the haptic interface caused a lower subjective satisfaction for some criteria. Generally, participants showed high subjective satisfaction levels and low subjective workloads toward haptic seat interfaces. This study provided guidance for implementing haptic seat interfaces and identified the possible benefits of their use. It is expected that haptic seats implemented in vehicles will improve safety and the interaction between driver and vehicle.

Social computing (n.d.) is defined by Wikipedia as “a general term for an area of computer science that is concerned with the intersection of social behavior and computational systems.” More specif...

The expansion of the social computing environment as a new basis for socioeconomic activities could enhance the quality of life of older adults, but also it could make the problem of digital divide more serious. In this study, the research directions and agenda of social computing for an aging society are presented, which have two major directions: basic study and applied study. Regarding human aspects in social computing mainly dealt with in the basic study, existing research and related theories on cognitive characteristics, information usage patterns, and social network site use of older adults were examined. In the applied study, a study about the most effective contents application and interfaces through user needs analysis, usage context analysis, prototype design, and so on, was conducted. Those studies are discussed to develop applications on a PC platform, mobile platform, and IPTV platform targeting the older adults population.

With the advent of Web 2.0, social network services (SNSs), such as Facebook and MySpace, have grown explosively and globally as one of core Web 2.0 applications. However, as revealed in other cultural comparison studies in the field of human–computer interaction, it is believed that cultural differences profoundly impact on how people use SNSs. Unfortunately, the differences in using SNSs have not been systematically investigated, so this study presents a web-based survey study among three nations: Republic of Korea, People's Republic of China, and the United States of America. It was assumed that SNS users form bridging and bonding social capital (borrowed from social capital theory) through the five functions of SNS that were categorized: Identity, Expert Search, Connection, Communication, and Contents Sharing. A correlation between social capital-related activities and usage patterns of SNS was expected. A total of 489 responded to the web-based survey through the three counties. Although the theory of cultural differences turned out to be insufficient to explain diverse usage patterns of SNSs, the results showed that Korean and Chinese users form bridging and bonding social capital mainly through Expert Search and Connection functions, but American users mainly use the Communication function to form bonding Social Capital. Various implications of these results for researchers and practitioners who work on and for SNSs are described as well.

Driver safety and workload have become a crucial issue as the telematics system has evolved in a complex manner. To solve this problem, the aim of this study is to develop a conceptual prototype that supports haptic interface, an eye-free technology, with free navigation based on the user's mental model. The conceptual prototype for haptic interface is established through identifying the problems with previous haptic interface devices and defining functional requirements for the next generation telematics system. In addition, 25 criteria for a haptic device design are identified and applied to evaluate the conceptual prototype. These criteria are classified in a hierarchical order, and an Analytic Hierarchy Process (AHP) evaluation model is constructed accordingly. The AHP evaluation framework reveals critical factors as well as the degree of importance in designing the haptic device. As a result, an evaluation method has been developed for the prototype of the early phase of the haptic device design.

(2006). Editorial: HCI Innovations in Korea. International Journal of Human–Computer Interaction: Vol. 20, No. 3, pp. 169-170.

In the last decade, the research of the usability of mobile phones has been a newly evolving area with few established methodologies and realistic practices that ensure capturing usability in evaluation. Thus, there exists growing demand to explore appropriate evaluation methodologies that evaluate the usability of mobile phones quickly as well as comprehensively. This study aims to develop a task-based usability checklist based on heuristic evaluations in views of mobile phone user interface (UI) practitioners. A hierarchical structure of UI design elements and usability principles related to mobile phones were developed and then utilized to develop the checklist. To demonstrate the practical effectiveness of the proposed checklist, comparative experiments were conducted on the usability checklist and usability testing. The majority of usability problems found by usability testing and additional problems were discovered by the proposed checklist. It is expected that the usability checklist proposed in this study could be used quickly and efficiently by usability practitioners to evaluate the mobile phone UI in the middle of the mobile phone development process.

This article reports the results of a survey conducted in 2003 of 184 information technology (IT) development practitioners and 90 user interface (UI)/usability practitioners. The survey covered a broad range of issues including the respondents' profiles, current development environment, usability and user-centered design (UCD) adoption issues in Korean IT development environments, overall assessment of UCD/usability, and the most widely used methods and techniques. The results reveal various UCD/usability practices and problems in the IT industry. For both development practitioners and UI/usability practitioners, the most serious problems encountered in a project are the differences between output and customer requirements, as well as further requirements from customer, delays in a project schedule, and overages on project budgets. The degree of recognition of usability/UCD is higher than expected, but UCD/usability is not yet fully employed in the project, because 42% of respondents used usability/UCD. Profiles from UI/usability practitioners and projects show a relatively weak position and short HCI tradition in the Korean IT industry. This study is expected to provide both an empirical basis for usability and UCD planning, training, adoption, and execution in the IT industry of Korea and an important information source for many HCI practitioners outside Europe and the United States who struggle to introduce usability into their IT industries.

Based on previous research and properties of organizational memory, a conceptual model for navigation and retrieval functions in an Intranet portal organizational memory information system was proposed, and two human-centred features (memory structure map and history-based tool) were developed to support user's navigation and retrieval in a well-known organizational memory. To test two hypotheses concerning the validity of the conceptual model and two human-centred features, an experiment was conducted with 30 subjects. Testing of the two hypotheses indicated the following: (1) the memory structure map's users showed 29% better performance in navigation, and (2) the history-based tool's users outperformed by 34% in identifying information. The results of the study suggest that a conceptual model and two human-centred features could be used in an user-adaptive interface design to improve user's performance in an intranet portal organizational memory information system.