Partial user-supplied information and user modeling for improving QoS

The incorporation of user-supplied information has become mandatory for the improvement of QoS in network systems. There is the question about accommodation of new users of a service, given that information about former users of a service is available. In the present work, we followed two approaches to derive information about new users in the network design and control processes, where both are based on prototype generation for the answers of former users to a QoS related questionnaire. In the first approach, attempts were made to map user attributes to prototypes. The second approach used a mapping from partial answers to a prototype. As a result, the first approach appeared to be infeasible, while the second showed good results. In the resulting trade-off between number of prototypes and classification accuracy, it is possible, for example, with 8 prototypes for around 1000 users to predict the answers of new users by using only 30% of the answers of former users, while reducing accuracy by only 13% at the same time.     

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.     

Prototyping strategies for multisensory product experience engineering

The paper deals with prototyping strategies aimed at supporting engineers in the design of the multisensory experience of products. It is widely recognised that the most effective strategy to design it is to create working prototypes and analyse user’s reactions when interacting with them. Starting from this consciousness, we will discuss of how virtual reality (VR) technologies can support engineers to build prototypes suitable to this aim. Furthermore we will demonstrate how VR-based prototypes do not only represent a valid alternative to physical prototypes, but also a step forward thanks to the possibility of simulating and rendering multisensory and real-time modifiable interactions between the user and the prototype. These characteristics of VR-based prototypes enable engineers to rapidly test with users different variants and to optimise the multisensory experience perceived by them during the interaction. The discussion is supported both by examples available in literature and by case studies we have developed over the years on this topic. Specifically, in our research we have concentrated on what happens in the physical contact between the user and the product. Such contact strongly influences the user’s impression about the product.     

Developing a navigation aid for the frail and visually impaired

This paper describes the development of a new navigational aid for the frail, elderly, and visually impaired person. The users were involved both in the user requirements study and in the evaluation of different prototypes. The results show that the users were able to provide information on their current aid, the use situation, and their preference regarding different solutions, but they had difficulties to provide the detailed answers on technical solutions required by the technical development team. Further, prototype evaluations with users enabled the technical team to understand the users and their use situation.     

A virtual prototyping system for rapid product development

This paper describes a virtual prototyping (VP) system that integrates virtual reality with rapid prototyping (RP) to create virtual or digital prototypes to facilitate product development. The proposed VP system incorporates two new simulation methodologies, namely the dexel-based and the layer-based fabrication approaches, to simulate the powder-based and the laminated sheet-based RP processes, respectively. The dexel-based approach deposits arrays of solid strips to form a layer, while the layer-based approach directly forms a complete layer by extruding the slice contours. The layer is subsequently stacked up to fabricate a virtual prototype. The simulation approaches resemble the physical fabrication processes of most RP systems, and are therefore capable of accurately representing the geometrical characteristics of prototypes. In addition to numerical quantification of the simulation results, the system also provides stereoscopic visualisation of the product design and its prototype for detailed analyses. Indeed, the original product design may be superimposed on its virtual prototype, so that areas with dimensional errors beyond design limits may be clearly highlighted to facilitate point-to-point analysis of the surface texture and the dimensional accuracy of the prototype. Hence, the key control parameters of an RP process, such as part orientation, layer thickness and hatch space, may be effectively tuned up for optimal fabrication of physical prototypes in subsequent product development. Furthermore, the virtual prototypes can be transmitted via the Internet to customers to facilitate global manufacturing. As a result, both the lead-time and the product development costs can be significantly reduced.     

Improving accessibility of mobile devices with EasyWrite

This paper describes the development process of EasyWrite, a text-entry method for mobile devices that allows people with hand coordination problems to use small computer devices such as smartphones, tablet PCs, or other touchscreen machines. This text-entry method aims at improving typing accuracy and reducing frustration of people affected by this motor disability when using small devices. EasyWrite was developed following an iterative and user-centred process. Starting from requirements elicited from observing potential users with mild and moderate motor disabilities and information provided by a literature review, a low-fidelity prototype was built and evaluated. This early prototype was refined throughout several design and evaluation iterations. Its current state is a functional prototype that works on Android phones. The functional prototype usability was evaluated through user tests. The result of this process is a small virtual keyboard for mobile devices that has less and bigger keys as compared to other onscreen keyboards. The concept of EasyWrite is largely based on the notion of scanning group systems, but it allows users to navigate directly through groups and subgroups of characters by tapping on directional keys in order to find the desired character rather than waiting for a visual cursor to advance through the options, one at a time, at a specific time rate. Though at its current stage the method proposed by EasyWrite shows some limitations, it appears to be appropriate for users with moderate motor disabilities. For this group of people, user test results indicate that EasyWrite could be a more adequate text-entry method than the one provided by standard keyboards, both physical and onscreen, commonly found in mobile devices.     

Participatory evaluation of an educational game for social skills acquisition

This paper reports a study conducted to formally evaluate a social problem-solving skills game during the start of the development to ensure that the desired game attributes were successfully embodied in the final game. Two methods, heuristic evaluation and participatory design, were adopted to assess whether the features of the game pose playability issues to the prospective young users and to translate the participants' contributions into game design directions. The participants playtested and evaluated the game based on the Pedagogical Playability Heuristics, which are different from existing heuristics developed for commercial games, as priority was placed on instructional design principles and the concept of playability. Using storyboarding, they built low-fidelity prototypes of the game. Suitable children's design and feedback on the games attributes that would bring about stimulation, connecting instructions to goals, appropriate challenge and influencing goal achievement were integrated into the game design. As a consequence of the study, steps were taken to improve the game as an interactive system to achieve the instructional goals and at the same time foster enjoyment among the users.     

Design and evaluation of online multimedia maintenance manuals

Maintenance in production environments is becoming increasingly complex as machines become more technologically advanced and need less maintenance. As a result, maintenance personnel face more difficult tasks. At the same time the maintenance engineers obtain less experience with the tasks. In this context, online multimedia manuals are thought to give better support for searching information and expressing complex interactions with physical objects than paper manuals. Three prototypes were designed and formative evaluated in an industrial environment. The evaluation of the first prototype showed that maintenance engineers encountered serious problems with the online multimedia manual, as they omitted crucial steps in the task. The second prototype addressed this problem. The third prototype addressed a problem observed in the second prototype when subjects switched between the online manual and the machine controls.     

Interface design and engagement with older people

The current paper examines the design process that led to an unusually successful interactive tutorial for older people. The paper describes the issues that make designing for older people different. These include differences between the designer and the target population and the difficulty that older people have in interacting with low-fidelity prototypes. Ways of altering the design process to address these issues and to obtain useful design contributions from older participants are described.     

MOPG: a multi-objective evolutionary algorithm for prototype generation

Prototype generation deals with the problem of generating a small set of instances, from a large data set, to be used by KNN for classification. The two key aspects to consider when developing a prototype generation method are: (1) the generalization performance of a KNN classifier when using the prototypes; and (2) the amount of data set reduction, as given by the number of prototypes. Both factors are in conflict because, in general, maximizing data set reduction implies decreasing accuracy and viceversa. Therefore, this problem can be naturally approached with multi-objective optimization techniques. This paper introduces a novel multi-objective evolutionary algorithm for prototype generation where the objectives are precisely the amount of reduction and an estimate of generalization performance achieved by the selected prototypes. Through a comprehensive experimental study we show that the proposed approach outperforms most of the prototype generation methods that have been proposed so far. Specifically, the proposed approach obtains prototypes that offer a better tradeoff between accuracy and reduction than alternative methodologies.     

A Context/Communication Information Agent

We are developing a Context/Communication Information Agent (CIA), an autonomous software agent that proactively searches for the right information at the right time. Our goal is to design and evaluate a system that leverages what people naturally do, using this knowledge to retrieve information, and presenting it with a minimal cost of disruption to the users. In this paper, we describe the results a low-fidelity prototype performed in a meeting situation, the design space for such an application, and our plans for continued investigation.     

Improving ecological performance of electrical consumer products: the role of design-based measures and user variables

This research is concerned with the ecological performance of electrical consumer products. It examines the influence of design-based measures on various ecological performance parameters and the relationship of user variables and performance. In the experimental scenario, 40 users were asked to clean a room with a vacuum cleaner under different conditions. In a multi-factorial design, the following independent variables were employed: on-product information, enhanced display-control labelling and proximity of controls. Measures of user variables (environmental concern, knowledge, habits) of ecological behaviour were also taken. The results showed that enhanced display-control labelling improved ecological performance but only when the label was placed close to the user. On-product information only resulted in behavioural change when it was in close spatial proximity to the control device. A positive effect on ecological performance was also observed when controls were in a proximal rather than distal position. Among user variables, habits were found to have an influence on behaviour shown in experimental scenarios. A practical implication of the findings for environmentally friendly design of consumer products is that there should be a stronger focus on system-based measures rather than information-based measures. Finally, the article discusses the theoretical implications of using operational scenarios rather than the information display board paradigm.     

Differential evolution for optimizing the positioning of prototypes in nearest neighbor classification

Nearest neighbor classification is one of the most used and well known methods in data mining. Its simplest version has several drawbacks, such as low efficiency, high storage requirements and sensitivity to noise. Data reduction techniques have been used to alleviate these shortcomings. Among them, prototype selection and generation techniques have been shown to be very effective. Positioning adjustment of prototypes is a successful trend within the prototype generation methodology.Evolutionary algorithms are adaptive methods based on natural evolution that may be used for searching and optimization. Positioning adjustment of prototypes can be viewed as an optimization problem, thus it can be solved using evolutionary algorithms. This paper proposes a differential evolution based approach for optimizing the positioning of prototypes. Specifically, we provide a complete study of the performance of four recent advances in differential evolution. Furthermore, we show the good synergy obtained by the combination of a prototype selection stage with an optimization of the positioning of prototypes previous to nearest neighbor classification. The results are contrasted with non-parametrical statistical tests and show that our proposals outperform previously proposed methods.     

Exploring multi-user interactions with dynamic NFC-displays

Near Field Communication (NFC) is an emerging technology for touch-based mobile interactions with single- and multi-tagged objects. Although the latter may allow for simultaneous and collaborative interactions, most prototypes were not designed for multiple users and were only evaluated with single-user interactions. In this paper, we investigate the design, usability and user experience of multi-user interactions on dynamic NFC-displays. These interactive surfaces use a grid of NFC-tags for the direct manipulation of projected application user interfaces. In two user studies with three prototypes for multi-user interaction, we evaluated the performance of dynamic NFC-displays, interactions among users and the interplay between mobile devices and large displays.     

The PROTEVS approach: A short presentation of background,principles and methods

Prototyping is not a new approach to computer-based information system development. It is just one technique among many used in system design. What might be new is for what purpose prototyping is used. The purpose could be to achieve a more user controlled system development and to give the future users a tool that will enable them to fully participate in not only the work with requirements specifications, but also in the actual systems design and organisational change. This paper describes a working model of an approach-the PROTEVS model-in which it is recommended that the future system users design their own prototype systems. The prototypes may act as both requirements specifications and solutions for actual change. This alternative approach aims to offer a basis for new ways of action for future users as participants in the design, evaluation, and change of a workplace. A suitable environment for the approach to act within is also described—a local design shop.     

Prototype learning for structured pattern representation applied to on-line recognition of handwritten Japanese characters

This paper describes prototype learning for structured pattern representation with common subpatterns shared among multiple character prototypes for on-line recognition of handwritten Japanese characters. Prototype learning algorithms have not yet been shown to be useful for structured or hierarchical pattern representation. In this paper, we incorporate cost-free parallel translation to negate the location distributions of subpatterns when they are embedded in character patterns. Moreover, we introduce normalization into a prototype learning algorithm to extract true feature distributions in raw patterns to aggregate distributions of feature points to subpattern prototypes. We show that our proposed method significantly improves structured pattern representation for Japanese on-line character patterns.     

上海中产家庭食空间·新产品战略·角色原型开发

为了寻找上海中产阶级家庭的厨房和餐厅空间的新产品市场,本课题应用人种志的方法收集用户的真实数据,而后以角色法呈现这个用户群体中5种不同类型的典型原型用户,并对其一做了详细的介绍,从而指导未来的新产品市场战略。     

Local feature weighting in nearest prototype classification.

The distance metric is the corner stone of nearest neighbor (NN)-based methods, and therefore, of nearest prototype (NP) algorithms. That is because they classify depending on the similarity of the data. When the data is characterized by a set of features which may contribute to the classification task in different levels, feature weighting or selection is required, sometimes in a local sense. However, local weighting is typically restricted to NN approaches. In this paper, we introduce local feature weighting (LFW) in NP classification. LFW provides each prototype its own weight vector, opposite to typical global weighting methods found in the NP literature, where all the prototypes share the same one. Providing each prototype its own weight vector has a novel effect in the borders of the Voronoi regions generated: They become nonlinear. We have integrated LFW with a previously developed evolutionary nearest prototype classifier (ENPC). The experiments performed both in artificial and real data sets demonstrate that the resulting algorithm that we call LFW in nearest prototype classification (LFW-NPC) avoids overfitting on training data in domains where the features may have different contribution to the classification task in different areas of the feature space. This generalization capability is also reflected in automatically obtaining an accurate and reduced set of prototypes.     

Nearest prototype classification of noisy data

Nearest prototype approaches offer a common way to design classifiers. However, when data is noisy, the success of this sort of classifiers depends on some parameters that the designer needs to tune, as the number of prototypes. In this work, we have made a study of the ENPC technique, based on the nearest prototype approach, in noisy datasets. Previous experimentation of this algorithm had shown that it does not require any parameter tuning to obtain good solutions in problems where class limits are well defined, and data is not noisy. In this work, we show that the algorithm is able to obtain solutions with high classification success even when data is noisy. A comparison with optimal (hand made) solutions and other different classification algorithms demonstrates the good performance of the ENPC algorithm in accuracy and number of prototypes as the noise level increases. We have performed experiments in four different datasets, each of them with different characteristics.