Luca Mainetti

Hypermedia design, analysis, and evaluation issues

ence both in developing several hypermedia applications , and systematically inspecting and evaluating many commercial applications and prototypes. We evaluate an application by its very nature, our method addresses neither software design (which can be evaluated with general software evaluation techniques), nor how well the application relates to a domain or to specific user needs (a main concern of other usabili-ty evaluation techniques). Our approach complements more general evaluation methods [1, 11, 12, 18, 19, 21] for the field of hypermedia. In this article we describe our design-oriented evaluation method and apply it to a highly popular commercial application: Microsofts Art Gallery, a hypermedia guide to the National Gallery in Lon-dons painting collection. Art Gallery is an outstanding and enjoyable application. Initially designed only for the museums visitors [20], it is now widely available as a CD-ROM [17]. We also discuss aspects of reuse in hypermedia applications and propose some initial suggestions for designing for reuse. Analysis Dimensions We have identified several dimensions for analyzing a hypermedia application: content, structure, presentation , dynamics, and interaction. • Content: The pieces of information included in the application. These may consist of static (passive) media (such as formatted data, text strings, images, and graphics) or active (dynamic) media (such as video clips, sound tracks, and anima-F r a n c a G a r z o t t o , L u c a M a i n e t t i , ne can perform a heuristic evaluation of a hypermedia application effectively by coupling a systematic analysis of the application based on a hypermedia design model with general usability criteria, independent of the specific application area, user profile(s), and user task(s). We call our method design-oriented evaluation (as opposed to the user-oriented evaluation commonly applied in usability testing), since it evaluates the internal strength of the design underlying the hypermedia application.

A survey on indoor positioning systems

This paper aims to provide the reader with a review of the main technologies explored in the literature to solve the indoor localization issue. Furthermore, some systems that use these enabling technologies in real-world scenarios are presented and discussed. This could deliver a better understanding of the state-of-the-art and motivate new research efforts in this promising field. Finally, focusing on one of the major challenges in the indoor localization field, i.e., the indoor animal tracking, existing indoor tracking systems have been reviewed and compared by analyzing advantages and drawbacks.

Navigation in hypermedia applications: modeling and semantics

Navigation—browsing from one related piece of information to another—is an important means of accessing information for a large class of applications: hypermedia, object‐oriented databases, multimedia databases, and even traditional systems. In this article, we discuss a variety of sophisticated navigation paradigms. We distinguish among free, guided tour and history‐based navigation. In addition, we discuss integrating pure browsing with query‐based access. We discuss static and dynamic models of the various navigation patterns, highlighting the fact that defining an adequate browing semantics requires a data model and a runtime model, both of which are more complex than those commonly found in hypermedia or databases. We illustrate these concepts with examples from a real‐life banking application.

Adding multimedia collections to the Dexter Model

The Dexter Model defines the notion of atomic components and composite components, but it does not prescribe, nor it suggests, any particular structure for composite components. This paper proposes a specific type of composite component, called “collection”. A collection is a container holding several members. Collections can contain other collections (nested collections). Collections can be regarded as sets, but they can also have an inner structure. Collections can be created in several ways: manually, through queries, by operations on other collections, by exploiting links, etc. Collections introduce a navigational pattern, based on their structure, that is different from the standard node&link navigation. If active media are considered, collections allow the design and implementation of complex synchronisation strategies, difficult to obtain otherwise. The paper describes the motivations for using collections, their structure, their navigational capabilities and a number of possible authoring mechanisms. It also examines the interplay between standard navigation and collection navigation, possible synchronization strategies for collections, as well as the requirements for the definition of a runtime support (which could be used to extend the runtime layer of the Dexter Model).

Information reuse in hypermedia applications

Reuse — broadly defined as the use of existing information objects or software artifacts in different contexts and for different purposes — is a technology for improving productivity, reducing the production effort and cost, and increasing the quality of end applications (promoting consistency and therefore improving usability). Reuse is a crucial issue in hypermedia applications. Reuse may be applied to items of different sizes and different complexity (from an elementary value to a large structured portion of the application). It may involve several aspects of the hypermedia application (content, organisation, presentation and connections). It can be implemented with different techniques, by creating a new copy of an item, or by sharing the same item in two (or more) different contexts. In this paper we analyse hypermedia reuse under these different viewpoints, discuss a classification of different types of reuse, and present a few examples from commercial and prototype hypermedia titles. From the analysis of these case studies we derive technical hints, recommendations and pitfalls-to-avoid, that would help hypermedia authors handle reuse in the most effective way possible. We also suggest reuse techniques that can be incorporated in future authoring systems.

Hypermedia Application Design: a Structured Approach

Hypermedia design is the task of specifying representation structures, dynamic behaviour, navigation patterns, and lay-out features, of a hypermedia application. This paper describes a structured approach to hypermedia design, identifying the crucial steps in the design process. Our main goal is to provide a guideline to make hypermedia design more systematic and better organised, and to help mastering the complexity of hypermedia application development and improving consistency and usability of the resulting applications.

Assertions to better specify the amazon bug

Modern Web applications are mainly distributed systems that exploit the Internet as communication means and the Web as neutral interface to access services and data. The addition of services to Web applications poses problems that are usually tackled at the technology level, but that should be addressed during design to deliver quality Web applications. A typical example of these problems is the Amazon bug, an annoying problem that the user could encounter if after adding products to his shopping cart, he rolls back to a page with a previous version of the cart and tries to buy it. This would make the user buy the last version of the carts contents, which in some subtle cases could be different from what expected.In this paper, we do not want to discuss all design aspects, but only how provided services/operations should jointly be designed with the rest of the system. We propose a new reference model for Web applications: Operations require a more complex model where they are not simply appended to information and navigation elements, but they can cooperate with them. Besides the reference model, the paper proposes the use of assertions to constraint the behavior of designed operations. Assertions do not only predicate on how data should be modified, but must also take into account how presentation and navigation could be affected by the execution of the operation.

Smart RFID Antenna System for Indoor Tracking and Behavior Analysis of Small Animals in Colony Cages

Radio frequency identification (RFID) technology is more and more adopted in a wide range of applicative scenarios. Nevertheless, in many applications, commercial and general-purpose solutions can be unsuitable as in the case of the tracking of small-size living animals for the behavior analysis. In such a case, the whole RFID hardware, as well as the control software, should be opportunely tailored for the particular application. In this paper, a novel RFID-based approach enabling an effective localization and tracking of small-sized laboratory animals is proposed. It is mainly based on a near-field (NF) RFID multiantenna system working in the UHF bandwidth, to be placed below the animals cage, and able to rigorously identify the NF RFID tags implanted in laboratory animals. Once the requirements of the reader antenna have been individuated, an antenna system composed of a matrix of specifically designed segmented loops has been prototyped. Moreover, to improve the effectiveness of the whole tracking system, a properly algorithm based on the measured received signal strength indication has been developed and integrated. It aims at removing potential minor ambiguities of the data captured by the multiantenna system. The whole animal tracking system has been then largely tested on phantom mice to verify its ability to precisely localize each subject and to reconstruct its path. Additionally, a first test performed on living mice has been presented. The achieved and discussed results demonstrate the effectiveness of the proposed approach.

RFID, EPC and B2B convergence towards an item-level traceability in the pharmaceutical supply chain

The item-level tagging is one of the main challenges of many application scenarios. Among these, the pharmaceutical supply chain represents a very interesting case where the new auto-identification technologies, based on RFID and EPCglobal, will play a very import role. The authors present practical experiences gained from a recent research project on the item-level traceability in the pharmaceutical supply chain. Furthermore, a discussion on several areas of improvement opportunities for future large-scale deployments of these technologies is reported.

W2000: A Modelling Notation for Complex Web Applications

This chapter presents W2000, a complete notation for modelling complex Web applications. All W2000 concepts are based on a precise meta-model that characterises the different notation elements and identifies the relationships between them. After introducing the modelling concepts and the hierarchical organisation of W2000 models, the chapter exemplifies the main modelling features through a case study and clarifies some design alternatives. The chapter also describes the tool support offered by W2000.