Eduardo Mosqueira-Rey

Usability: A Critical Analysis and a Taxonomy

A major obstacle to the implantation of User-Centered Design in the real world is the fact that no precise definition of the concept of usability exists that is widely accepted and applied in practice. Generally speaking, the literature tends to define usability in overly brief and ambiguous terms and to describe its application in informal terms. This is one of the main reasons why ad hoc techniques predominate in usability study methodologies. The aims of this article are to investigate the concept of usability and to describe it by means of a detailed taxonomy that is organized hierarchically and that contains exhaustive descriptions of usability attributes. This taxonomy can be used to support different stages in the development of usable systems.

Validation of intelligent systems: a critical study and a tool

Abstract One of the most important phases in the methodology for the development of intelligent systems is that corresponding to the evaluation of the performance of the implemented product. This process is popularly known as verification and validation (V&V). The majority of tools designed to support the V&V process are preferentially directed at verification in detriment to validation, and limited to an analysis of the internal structures of the system. The authors of this article propose a methodology for the development of a results-oriented validation, and a tool (SHIVA) is presented which facilitates the fulfilment of the tasks included in the methodology, whilst covering quantitative as well as heuristic aspects. The result is an intelligent tool for the validation of intelligent systems.

Information analysis and validation of intelligent monitoring systems in intensive care units

The validation of intelligent systems is an important task to perform. Typically, the results of the validation analysis are used to verify whether or not the system satisfies the initial design requirements, and to acquire new knowledge and/or refine the knowledge already acquired. In practice, the validation of intelligent systems usually requires the application of several different techniques (e.g. retrospective, prospective and quantitative). In this paper, the authors present the methodology devised to validate PATRICIA: an intelligent monitoring system designed to advise clinicians on the management of patients who are dependent on mechanical ventilation. The application of this methodology requires that appropriate validation paradigms are selected, depending on both the application domain and the characteristics of the intelligent system. The article also presents and discusses validation results.

A Context-of-Use Taxonomy for Usability Studies

The interest in developing usable products has led to the inclusion of usability aspects in product development processes. Nonetheless, the fact that there is a tendency to overlook characteristics of the context in which a product is to be used means that the usability of a product in its operational environment is often diminished. One of the main reasons why this is the case is because there is no clear and sufficiently detailed model available for defining the concept of context of use. A comprehensive taxonomy that describes context of use and its attributes by means of precise definitions is proposed. This taxonomy will serve as a basis for improving the validity of usability activities by enabling an analysis of the conditions of use of a product in usability studies in a structured way.

Causal temporal constraint networks for representing temporal knowledge

In this work we describe causal temporal constraint networks (CTCN) as a new computable model for representing temporal information and efficiently handling causality. The proposed model enables qualitative and quantitative temporal constraints to be established, introduces the representation of causal constraints, and suggests mechanisms for representing inexact temporal knowledge. The temporal handling of information is achieved by structuring the information in different interpretation contexts, linked to each other through an inference mechanism which obtains interpretations that are consistent with the original temporal information. In carrying out inferences, we take into account the temporal relationships between events, the possible inexactitude associated with the events, and the atemporal or static information which affects the interpretation pattern being considered. The proposed schema is illustrated with an application developed using the CommonKADS methodology.

A Misuse Detection Agent for Intrusion Detection in a Multi-agent Architecture

We describe the design of a misuse detection agent, one of the different agents in a multiagent-based intrusion detection system. This system is being implemented in JADE, a well-known multiagent platform based in Java. The agent analyzes the packets in the network connections using a packet sniffer and then creates a data model based on the information obtained. This data model is the input to a rule-based agent inference engine, which uses the Rete algorithm for pattern matching, and the rules of the signature-based intrusion detection system Snort. Specifically, an implementation in Java language --- the Drools-JBoss Rules--- was used, and a parser was implemented that converts Snort rules to Drools rules. The use of object-oriented techniques, together with design patterns, means that the agent is flexible, easily configurable and extensible.

A Snort-based agent for a JADE multi-agent intrusion detection system

We describe the design of a misuse detection agent, one of the distinct agents in a multi-agent-based intrusion detection system. This system is being implemented in JADE, a well-known multi-agent platform based in Java. The agent analyses the packets in the network connections using a packet sniffer and then creates a data model based on the information obtained. This data model is the input to a rule-based inference engine agent, which uses the Rete algorithm for pattern matching and the rules of the signature-based intrusion detection system, Snort. Specifically, an implementation in Java language – the Drools-JBoss Rules – was used and a parser was implemented that converts Snort rules into Drools rules. The use of object-oriented techniques, together with design patterns, means that the agent is flexible, easily configurable and extensible.

Intelligent interpretation of validation data

Abstract This paper describes the characteristics of an expert system that will make an intelligent interpretation of the quantitative data obtained following the usual validation process for intelligent systems. This expert system converts numerical data into information that will indicate whether the performance of the validated intelligent system is comparable to the performance of human experts from the domain taken as reference. The process is carried out in two parts: an algorithmic part which identifies the basic characteristics of the quantitative data; a heuristic part which analyses these characteristics so as to be able to draw conclusions as to the results of the system.

A knowledge model for the development of a framework for hypnogram construction

Abstract We describe a proposal of a knowledge model for the development of a framework for hypnogram construction from intelligent analysis of pulmonology and electrophysiological signals. Throughout the twentieth century, after the development of electroencephalography (EEG) by Hans Berger, there have been multiple studies on human sleep and its structure. Polysomnography (PSG), a sleep study from several biophysiological variables, gives us the hypnogram, a graphic representation of the stages of sleep as a function of time. This graph, when analyzed in conjunction with other physiological parameters, such as the heart rate or the amount of oxygen in arterial blood, has become a valuable diagnostic tool for different clinical problems that can occur during sleep and that often cause poor quality sleep. Currently, the gold standard for the detection of sleep events and for the correct classification of sleep stages are the rules published by the American Academy of Sleep Medicine (AASM), version 2.2. Based on the standards available to date, different studies on methods of automatic analysis of sleep and its stages have been developed but because of the different development and validation procedures used in existing methods, a rigorous and useful comparative analysis of results and their ability to correctly classify sleep stages is not possible. In this sense, we propose an approach that ensures that sleep stage classification task is not affected by the method for extracting PSG features and events. This approach is based on the development of a knowledge-intensive base system (KBS) for classifying sleep stages and building the corresponding hypnogram. For this development we used the CommonKADS methodology, that has become a de facto standard for the development of KBSs. As a result, we present a new knowledge model that can be used for the subsequent development of an intelligent system for hypnogram construction that allows us to isolate the process of signal processing to identify sleep stages so that the hypnograms obtained become comparable, independently of the signal analysis techniques.

A Taxonomy-Based Usability Study of an Intelligent Speed Adaptation Device

Usability studies are often based on ad hoc definitions of usability. These studies can be difficult to generalize, they might have a steep learning curve, and there is always the danger of being inconsistent with the concept of usability as defined in standards and the literature. This alternative approach involves comprehensive, general-purpose, and hierarchically structured taxonomies that follow closely the main usability literature. These taxonomies are then instantiated for a specific product. To illustrate this approach, a usability study for a prototype of an Intelligent Speed Adaptation device is described. The usability study consists of usability requirements analysis, heuristic evaluation, and subjective analysis, which helped identify problems of clarity, operability, robustness, safety, and aesthetics. As a context-specific usability taxonomy for this particular field of application happened to exist, the way that real-world usability results can be mapped to that taxonomy compared to the taxonomy in this article is examined, with the argument that this study’s taxonomy is more complete and generalizable.