Evaluating Interface Design Choices on WAP Phones: Navigation and Selection

Wireless Application Protocol (WAP) phones are a growing relevant part of the mobile market, and the number of WAP services offered is rapidly increasing. Usability is crucial for these services, which must be easily operated on small screens and keyboards. Unfortunately, there are very few published studies on the evaluation of WAP devices and services on users. This paper presents a user study that evaluates two important interface design choices for WAP services (implementation of single-choice selection, and navigation among the different cards of a WAP site), neither of which has been investigated thoroughly in the literature or in design practice.     

Adaptive Hypermedia Techniques for 3D Educational Virtual Environments

Based on a well-known adaptive hypermedia framework, the proposed system creates a 3D educational virtual environment that selects and personalizes interactive learning content for users. In EVEs, users not only see concepts visualized, but they can perform tasks in a suitable fictional world or a real-world reproduction. Moreover, compared to 2D multimedia, using interactive 3D graphics lets developers create representations of subjects or phenomena that are more informative and make it possible for users to analyze a single subject from different viewpoints. In EVEs, adaptivity can play an important role in increasing both learning-process effectiveness and interface usability.     

Employing virtual humans for education and training in X3D/VRML worlds

Web-based education and training provides a new paradigm for imparting knowledge; students can access the learning material anytime by operating remotely from any location. Web3D open standards, such as X3D and VRML, support Web-based delivery of Educational Virtual Environments (EVEs). EVEs have a great potential for learning and training purposes, by allowing one to circumvent physical, safety, and cost constraints. Unfortunately, EVEs often leave to the user the onus of taking the initiative both in exploring the environment and interacting with its parts. A possible solution to this problem is the exploitation of virtual humans acting as informal coaches or more formal instructors. For example, virtual humans can be employed to show and explain maintenance procedures, allowing learners to receive more practical explanations which are easier to understand. However, virtual humans are rarely used in Web3D EVEs, since the programming effort to develop and re-use them in different environments can be considerable. In this paper, we present a general architecture that allows content creators to easily integrate virtual humans into Web3D EVEs. To test the generality of our solution, we present two practical examples showing how the proposed architecture has been used in different educational contexts.     

An Estimate for the Entropy of Hamiltonian Flows

In this paper, we present a generalization to Hamiltonian flows on symplectic manifolds of the estimate proved by Ballmann and Wojtkovski in [4] for the dynamical entropy of the geodesic flow on a compact Riemannian manifold of nonpositive sectional curvature. Given such a Riemannian manifold M, Ballmann and Wojtkovski proved that the dynamical entropy h _μ of the geodesic flow on M satisfies the inequalitywhere v is a unit vector in T _p M if p is a point in M, SM is the unit tangent bundle on M, K(v) is defined as , where is the Riemannian curvature of M, and μ is the normalized Liouville measure on SM. We consider a symplectic manifold M of dimension 2n, and a compact submanifold N of M, given by the regular level set of a Hamiltonian function on M; moreover, we consider a smooth Lagrangian distribution on N, and we assume that the reduced curvature of the Hamiltonian vector field with respect to the distribution is non-positive. Then we prove that under these assumptions, the dynamical entropy h _μ of the Hamiltonian flow with respect to the normalized Liouville measure on N satisfies      

Interactive Persuasive Systems: A Perspective on Theory and Evaluation

Interactive systems are increasingly used in a growing number of domains to encourage users to perform certain actions or take a certain position toward a given subject. This article offers a perspective on interactive persuasive systems that emphasizes theories and concepts that can guide their design and evaluation. The goal is not to champion a theoretical model over others or to compare the effectiveness of different persuasive strategies but rather to depict the current conceptual landscape in this field and highlight emerging concepts and positions that have recently appeared in it. The article includes a discussion of some representative, general, and domain-specific constructs that can be used to evaluate the effectiveness of interactive persuasive systems.     

Temporal representation and reasoning in artificial intelligence: Issues and approaches

Time is one of the most relevant topics in AI. It plays a major role in several areas, ranging from logical foundations to applications of knowledge‐based systems. In this paper, we survey a wide range of research in temporal representation and reasoning, without committing ourselves to the point of view of any specific application. The organization of the paper follows the commonly recognized division of the field in two main subfields: reasoning about actions and change, and reasoning about temporal constraints. We give an overview of the basic issues, approaches, and results in these two areas, and outline relevant recent developments. Furthermore, we briefly analyze the major emerging trends in temporal representation and reasoning as well as the relationships with other well‐established areas, such as temporal databases and logic programming. This revised version was published online in June 2006 with corrections to the Cover Date.     

Mobrex: visualizing users' mobile browsing behaviors.

This paper deals with the Mobile Browsing Explorer (Mobrex) to give analysts a set of interactive visualizations that highlight various aspects of how users browse an information space. Here, we describe the tool and demonstrate its support of a user study of three browsing techniques for mobile maps. Although we mainly focus here on PDAs and mobile map browsing, Mobrex can easily support analysts studying user interaction with other information spaces and other devices, including mobile phones and desktop computers.     

Personalized emergency medical assistance for disabled people

Being able to promptly and accurately choose a proper course of action in the field is a crucial aspect of emergency response. For this reason, emergency medical services (EMS) rely on well established procedures that apply to the most frequent cases first responders encounter in their practice, but do not include special cases concerning (sensory, motor or cognitive) disabled persons. In these cases, first responders may end up applying suboptimal or possibly wrong procedures or lose precious time trying to adapt on-the-fly to the special case. This paper proposes both (i) a detailed patient model for EMS that can account for peculiar aspects of the many existing disabilities and (ii) an adaptive information system called PRESYDIUM (Personalized Emergency System for Disabled Humans) that provides tailored instructions in the field for helping medical first responders in dealing with disabled persons. More precisely, we will illustrate and discuss: (i) the design and development process of PRESYDIUM, (ii) the patient model, which is partly based on the ICF (International Classification of Functioning, Disability and Health) standard proposed by the World Health Organization, (iii) the knowledge base used by the system to provide tailored instructions to medical first responders, (iv) the Web-based architecture of the system, (v) the different interfaces??including one for mobile devices??the system provides to enable all the identified stakeholders (disabled persons, their families, clinicians, EMS call center operators, medical first responders) to easily access and possibly provide data to the system, (vi) the evaluation of the validity of the patient model and of the system usability which has been conducted with end users.