The effects of usability and web design attributes on user preference for e-commerce web sites

This study examines the relationships among perceived usability before actual use, task completion time, and preference, and the effects of design attributes on user preference for e-commerce web sites. Nine online bookstore web sites were used by ten participants. Results indicate: (1) pre-use usability and task completion time were correlated; (2) the relationship between pre-use usability and preference was greater than that of task completion time and preference; (3) design attribute assessments after actual use were highly intercorrelated; and (4) organizational structure and layout had a greater effect on user preference than aesthetic aspects, such as color and typography. These findings can be used to construct a conceptual framework for understanding user preferences and to develop design guidelines to yield more highly preferred e-commerce web sites. Also, the methodology in this study can be applied to other computerized-applications.     

Effects of task complexity on individual creativity through knowledge interaction: A comparison of temporary and permanent teams

Using the interactionist’s perspective of creativity, this paper proposes a new research model of creativity manifestation to explore how factors affecting individual creativity depend on team characteristics. We investigated the antecedents of creativity in the literature—task complexity, team member exchange, and knowledge sharing—and then examined the relationships and differences between temporary and permanent teams. To maximize practical implications, we studied two team types like project task force (PTF) and research and development (R&D) teams in the Information and Communication Technology (ICT) industry in Korea, where strong creativity is required for team performance. PTF teams operate with a clear mission to be completed on a deadline, while R&D teams create scientific enhancements for existing products. The proposed structural model was tested empirically with cross-sectional data from 289 professionals from the two team types. Results indicated that, in the case of PTF teams, task complexity had an indirect relationship with individual complexity through knowledge interaction among team members, while for R&D teams, task complexity was directly associated with individual creativity, and indirectly associated with the creativity through team member exchange. Thus, team characteristics must be considered together with task complexity and knowledge interactions in order to achieve team goals more effectively by maximizing each member’s creativity.     

Software ergonomics: effects of computer application design parameters on operator task performance and health

Abstract

Evidence is reviewed that the operating characteristics of computer application systems, in addition to physical characteristics of display units (CRTs), are the cause of many observed effects on operator health and task effectiveness. These effects are hypothesized to occur through changes in task structure, and the man-machine redivision of labour that results when computer application systems are introduced into work setting. First, the association between task dimensions and models of operator performance effectiveness and well-being are reviewed. Second, application system design parameters that affect task structure are identified. Then, empirical evidence supporting this three-part causal linkage—application system parameters to task characteristics to operator effectiveness and health—is presented. The findings suggest that by improving dialogue quality, taking advantage of two-way communication to reduce uncertainty, using smaller and less integrated systems and matching system performance to operator needs a job can be created that is likely to improve both operator well-being and effectiveness.     

The influence of laboratory set-up in usability tests: effects on user performance,subjective ratings and physiological measures

This article examines the influences of situational factors on user behaviour in usability tests. Sixty participants carried out two tasks on a computer-simulated prototype of a mobile phone. Employing a 3 × 2 mixed experimental design, laboratory set-up was varied as a between-subjects variable (presence of facilitator and two non-interactive observers, presence of facilitator or no person present) while task difficulty was manipulated as a within-subjects variable (low vs. high). Performance data, subjective measures and physiological parameters (e.g. heart rate variability) were taken. The results showed that the presence of non-interactive observers during a usability test led to a physiological stress response, decreased performance on some measures and affected the emotional state of test participants. The presence of a facilitator (i.e. a participating observer) also influenced the emotional state of the test participant. Practitioners involved in usability testing need to be aware of undue influences of observers, in particular, if the observers are non-interactive. The findings presented in this paper have implications for the practice of usability testing. They indicated a considerable influence of observers on test participants (physiology and emotions) and on the outcomes of usability tests (performance measures). This should be considered when selecting the set-up of a usability testing procedure.     

Understanding the attitudes,knowledge sharing behaviors and task performance of core developers: A longitudinal study

ContextPrior research has established that a few individuals generally dominate project communication and source code changes during software development. Moreover, this pattern has been found to exist irrespective of task assignments at project initiation.ObjectiveWhile this phenomenon has been noted, prior research has not sought to understand these dominant individuals. Previous work considering the effect of team structures on team performance has found that core communicators are the gatekeepers of their teams’ knowledge, and the performance of these members was correlated with their teams’ success. Building on this work, we have employed a longitudinal approach to study the way core developers’ attitudes, knowledge sharing behaviors and task performance change over the course of their project, based on the analysis of repository data.MethodWe first used social network analysis (SNA) and standard statistical analysis techniques to identify and select artifacts from ten different software development teams. These procedures were also used to select central practitioners among these teams. We then applied psycholinguistic analysis and directed content analysis (CA) techniques to interpret the content of these practitioners’ messages. Finally, we inspected these core developers’ activities as recorded in system change logs at various points in time during systems’ development.ResultsAmong our findings, we observe that core developers’ attitudes and knowledge sharing behaviors were linked to their involvement in actual software development and the demands of their wider project teams. However, core developers appeared to naturally possess high levels of insightful characteristics, which became evident very early during teamwork.ConclusionsProject performance would likely benefit from strategies aimed at surrounding core developers with other competent communicators. Core developers should also be supported by a wider team who are willing to ask questions and challenge their ideas. Finally, the availability of adequate communication channels would help with maintaining positive team climate, and this is likely to mitigate the negative effects of distance during distributed developments.     

The influence of design aesthetics in usability testing: Effects on user performance and perceived usability

This article examined the effects of product aesthetics on several outcome variables in usability tests. Employing a computer simulation of a mobile phone, 60 adolescents (14-17 yrs) were asked to complete a number of typical tasks of mobile phone users. Two functionally identical mobile phones were manipulated with regard to their visual appearance (highly appealing vs not appealing) to determine the influence of appearance on perceived usability, performance measures and perceived attractiveness. The results showed that participants using the highly appealing phone rated their appliance as being more usable than participants operating the unappealing model. Furthermore, the visual appearance of the phone had a positive effect on performance, leading to reduced task completion times for the attractive model. The study discusses the implications for the use of adolescents in ergonomic research.     

The influence of prototype fidelity and aesthetics of design in usability tests: effects on user behaviour, subjective evaluation and emotion

An empirical study examined the impact of prototype fidelity on user behaviour, subjective user evaluation and emotion. The independent factors of prototype fidelity (paper prototype, computer prototype, fully operational appliance) and aesthetics of design (high vs. moderate) were varied in a between-subjects design. The 60 participants of the experiment were asked to complete two typical tasks of mobile phone usage: sending a text message and suppressing a phone number. Both performance data and a number of subjective measures were recorded. The results suggested that task completion time may be overestimated when a computer prototype is being used. Furthermore, users appeared to compensate for deficiencies in aesthetic design by overrating the aesthetic qualities of reduced fidelity prototypes. Finally, user emotions were more positively affected by the operation of the more attractive mobile phone than by the less appealing one.     

Do size and structure matter to mobile users? An empirical study of the effects of screen size, information structure, and task complexity on user activities with standard web phones

The small screens of mobile Internet devices, combined with the increasing complexity of mobile tasks, create a serious obstacle to usability in the mobile Internet. One way to circumvent the obstacle is to organize an information structure with efficient depth/breadth trade-offs. A controlled lab experiment was conducted to investigate how screen size and information structure affect user behaviours and perceptions. The moderating effects of task complexity on the relationship between screen size/information structure and user navigation/perceptions were also investigated. Study results indicate that both information structure and screen size significantly affect the navigation behaviour and perceptions of mobile Internet users. Task complexity was also found to heighten the influence of information structure on user behaviour and perceptions. The paper ends with a discussion of theoretical and practical implications, among them a key implication for mobile Internet businesses: for corporate intranet systems as well as m-commerce transaction systems, the horizontal depth of information structures should be adapted to task complexity and anticipated screen size.     

Driving monotonous routes in a train simulator: the effect of task demand on driving performance and subjective experience

Although monotony is widely recognised as being detrimental to performance, its occurrence and effects are not yet well understood. This is despite the fact that task-related characteristics, such as monotony and low task demand, have been shown to contribute to performance decrements over time. Participants completed one of two simulated train-driving scenarios. Both were highly monotonous and differed only in terms of the level of cognitive demand required (i.e. low demand or high demand). These results highlight the seriously detrimental effects of the combination of monotony and low task demands and clearly show that even a relatively minor increase in cognitive demand can mitigate adverse monotony-related effects on performance for extended periods of time. Monotony is an inherent characteristic of transport industries, including rail, aviation and road transport, which can have adverse impact on safety, reliability and efficiency. This study highlights possible strategies for mitigating these adverse effects. Practitioner Summary: This study provides evidence for the importance of cognitive demand in mitigating monotony-related effects on performance. The results have clear implications for the rapid onset of performance deterioration in low demand monotonous tasks and demonstrate that these detrimental performance effects can be overcome with simple solutions, such as making the task more cognitively engaging.     

Investigating the effects of experience on human performance in an object-tracking task: a case study of manual rendezvous and docking

Human involvement with the manual control of object-tracking tasks, such as manual rendezvous and docking, can enhance the flexibility of the task. The operator is required to make decisions as precisely as possible when a chase vehicle is approaching the target vehicle. As the level of mental workload is intensively increased, the operator's perception and decision-making with tracking error-correcting purposes should be properly identified in multiple degrees of freedom (DOFs). The two experimental studies in this paper were conducted for object-based selective attention in six DOFs and object-pointing manipulation under the zero resistance circumstance, which were correlated with human performance when a chaser approached a target spacecraft; the effects of experience level on the two important factors are presented herein. The experimental results demonstrated that some performance details between the novice and experienced groups were different in terms of the attentional priority of multiple DOFs and lateral/vertical movement for deviation error correction, which could provide a certain reference for a cognitive–behavioural model and assist the operator in obtaining proper or even optimal decision-making or operating instructions to improve their adaptation to selective attention and object-pointing manipulation, for preventing accidental manipulation and performance degradation.     

The effect of design on the usability and real world effectiveness of medical devices: A case study with adolescent users

Adolescents are currently overlooked in many fields of healthcare research and as a result are often required to use medical devices that have been designed for use by either children or adults. This can lead to poor adherence and a reduction in health outcomes.