Web Engineering at the Frontier of the Web 2.0: Design Patterns for Online 3D Shared Spaces

Online 3D Shared Spaces (3DSSs) can be regarded as a frontier of the Web 2.0, where users as participants contribute to create a meaningful, engaging experience. Like other complex web applications, the development and evolution of high-quality 3DSS applications requires methodological support—through models, methods, and principles. Yet, the application of structured, engineered approaches to this domain is largely unexplored. The purpose of this paper is to contribute to bridging Web Engineering to the 3DSS world by means of design patterns. We present five patterns that focus on two factors deemed necessary for effective experiences in a 3DSS: Presence (i.e. the feeling of “being there”, typical of “virtual worlds”) and Long-Term Engagement (typical of successful Web 2.0 communities). The patterns presented in the paper distil our large-scale experiences with 3DSSs (that have involved so far over 9,000 youngsters from 3 continents) and are discussed in the light of existing literature.     

User interface patterns in recommendation-empowered content intensive multimedia applications

Design Patterns (DPs) are acknowledged as powerful conceptual tools to improve design quality and to reduce time and cost of the development process by effect of the reuse of “good” design solutions. In many fields (e.g., software engineering, web engineering, interface design) patterns are widely used by practitioners and are also investigated from a research perspective. Still, they have been seldom explored in the arena of Recommender Systems (RSs). RSs provide suggestions (“recommendations”) for items that are likely to be appropriate for the user profile, and are increasingly adopted in content-intensive multimedia applications to complement traditional forms of search in large information spaces. This paper explores RSs through the lens of User Interface (UI) Design Patterns. We have performed a systematic analysis of 54 recommendation-empowered content-intensive multimedia applications, in order to: (i) discover the occurrences of existing domain independent UI patterns; (ii) identify frequently adopted UI solutions that are not modelled by existing patterns, and define a set of new UI patterns, some of which are specific of the interfaces for recommendation features while others can be useful also in a broader context. The results of our inspection have been discussed with and evaluated by a team of experts, leading to a consolidated set of 14 new patterns that are reported in the paper. Reusing pattern-based design solutions instead of building new solutions from scratch enables novice and expert designers to build good UIs for Recommendation-empowered content intensive multimedia applications more effectively, and ultimately can improve the UX experience in this class of systems. From a broader perspective, our work can stimulate future research bridging Recommender Systems, Web Engineering and Interface Design by means of Design Patterns, and highlights new research directions also discussed in the paper.

     

MemHolo: mixed reality experiences for subjects with Alzheimer’s disease

HoloLens is the most recent and advanced forms of wearable Mixed Reality (MR) technology. It enables the user wearing a head-mounted device to experience 3D holographic objects “inside” the visualization of the real environment where he or she is located. Existing HoloLens applications have been developed in domains such as data visualization, entertainment, industrial training, education, and tourism, but the use of this technology in the arena of mental health is largely unexplored. The paper presents a HoloLens-based system called MemHolo that addresses persons with mild Alzheimer’s Disease (AD). AD is associated to a chronic progressive neurodegenerative process that severely affects cognitive functioning (especially memory) and some motor functions. MemHolo is intended to be used as a cognitive training tool to practice short-term and spatial memory in a safe and controlled virtual environment, and to mitigate the effects of mental decline. The paper discusses the design process of MemHolo, and describes three evaluation studies on progressive prototypes. To our knowledge, MemHolo is the first HoloLens application designed natively for persons with AD. Our empirical work sheds a light on how these people experience HoloLens applications, highlights some challenges and potential benefits of using MR technology in the AD arena, and may pave the ground towards new forms of treatment.

     

HIFI: Hypertext interface for information systems

HIFI is one of the Esprit III information-processing system and software projects. The goal of HIFI is to create a set of tools that can be used to cheaply and quickly build a hypertext-like interface on top of an external database-information system. The interface provides interactive navigational access to information both within a database of one kind and across databases of different kinds, including multimedia. HIFI's model for the navigational interface, mapping strategy to map the interface model to database structures, and architecture for the execution tools are discussed     

SUE inspection: an effective method for systematic usabilityevaluation of hypermedia

SUE inspection is a novel usability evaluation method for hypermedia, which falls into the category of inspection methods. Its primary goal is to favor a systematic usability evaluation (SUE), for supplying hypermedia usability inspectors with a structured flow of activities, allowing them to obtain more reliable, comparable, and cost-effective evaluation results. This is obtained especially due to the use of evaluation patterns, called abstract tasks (AT), which describe in details the activities that evaluators must carry out during inspection. AT helps share and transfer evaluation know-how among different evaluators, thus making it easier to learn the SUE inspection method by newcomers. A further notable advantage provided by the SUE inspection over other existent approaches is that it focuses on navigation and information structures, making evident some problems that other "surface-oriented" approaches might not reveal. This paper describes the SUE inspection for hypermedia. It also reports on a validation experiment, involving 28 evaluators, that has shown the major effectiveness and efficiency of the SUE inspection for hypermedia, with respect to traditional heuristic evaluation techniques     

Aspects of suicide and parsuicide

Five aspects of suicidal behaviour in Edinburgh from 1968 to 1974 were examined. The data referred to 478 suicidal deaths and to parasuicide (attempted suicide) admissions to the Regional Poisoning Treatment Centre (R.P.T.C.). Firstly: 28% of suicides were found to have had a parasuicide admission and there was some evidence of a slight excess of deaths in the years immediately following parasuicide. Secondly: among suicides preceded by parasuicide, those with a recent episode (within 2 years of death) were found to be essentially similar to those with a longer interval. Thirdly: a history of previous parasuicide at any time was found to be important in delineating two groups of suicide. Suicides with prior parasuicide died more often from poisoning with drugs and were more likely to have a history of psychiatric treatment; suicides without prior parasuicide died more often from poisoning with domestic gas or violent means, were older, of higher social class and less often married. Fourthly: parasuicides who killed themselves within 2 years of admission to the R.P.T.C. were compared with a group of (broadly nonsuicidal) parasuicides. And lastly: a scale predictive of repetition of parasuicidal behaviour was used in an attempt to distinguish parasuicides who killed themselves from those who did not. The scale did not discriminate between the two groups.     

Hypertext development using a model-based approach

Hypertext development is still, for the most part, at the ‘handcrafting’ level, where each hypertext document must be hand-designed. We present a compiler which takes hyperdocuments designed using a model-based approach and generates stacks executable in Hyper Card. This compiler is implemented in standard SQL over a relational database representation of a hyperdocument designed using the hypermedia design model (HDM). The compiling approach, even though illustrated with HDM, can be used with any ‘structured’ design methodology.     

Photoinactivation of Pseudomonas aeruginosa Biofilm by Dicationic Diaryl-Porphyrin

In recent years, antimicrobial photodynamic therapy (aPDT) has received increasing attention as a promising tool aimed at both treating microbial infections and sanitizing environments. Since biofilm formation on biological and inert surfaces makes difficult the eradication of bacterial communities, further studies are needed to investigate such tricky issue. In this work, a panel of 13 diaryl-porphyrins (neutral, mono- and di-cationic) was taken in consideration to photoinactivate Pseudomonas aeruginosa. Among cationic photosensitizers (PSs) able to efficiently bind cells, in this study two dicationic showed to be intrinsically toxic and were ruled out by further investigations. In particular, the dicationic porphyrin (P11) that was not toxic, showed a better photoinactivation rate than monocationic in suspended cells. Furthermore, it was very efficient in inhibiting the biofilms produced by the model microorganism Pseudomonas aeruginosa PAO1 and by clinical strains derived from urinary tract infection and cystic fibrosis patients. Since P. aeruginosa represents a target very difficult to inactivate, this study confirms the potential of dicationic diaryl-porphyrins as photo-activated antimicrobials in different applicative fields, from clinical to environmental ones.