Angélica de Antonio

A proposal for student modeling based on ontologies and diagnosis rules

The advances in the educational field and the high complexity of student modeling have provoked it to be one of the aspects more investigated in Intelligent Tutoring Systems (ITSs). The Student Models (SMs) should not only represent the students knowledge, but rather they should reflect, as faithfully as possible, the students reasoning process. To facilitate this goal, in this article a new approach to student modeling is proposed that benefits from the advantages of Ontological Engineering, advancing in the pursue of a more granular and complete knowledge representation. Its focused, mainly, on the SM cognitive diagnosis process, and we present a method providing a rich diagnosis about the students knowledge state - especially, about the state of learning objectives reached or not. The main goal is to achieve SMs with a good adaptability to the students features and a high flexibility for its integration in varied ITSs.

Intelligent virtual environments for training: an agent-based approach

In this paper we propose an architecture for the development of Intelligent Virtual Environments for Training, which is based on a collection of cooperative software agents. The first level of the architecture is an extension of the classical Intelligent Tutoring System architecture that adds to the expert, student, tutoring and communication modules a new module which is called World Module. Several software agents compose each module. Moreover, the proposed architecture includes agents able to simulate the behavior of human students and tutors, as well as agents able to plan the procedures to be taught (given an initial state and a desired final state) prior to the tutoring process.

When emotion does not mean loss of control

The traditional consideration that intelligent behaviors can only be produced from pure reasoning fails when trying to explain most of human behaviors, in which the emotional component has a decisive weight. However, although many different efforts have been made to consider emotions in the rational process, emotion is still perceived by many research areas as a non-desirable quality for a computational system. This is not the case of the field of believable agents, where emotions are well respected, although they are sometimes associated to a certain loss of control.This paper presents the mechanisms proposed by a generic cognitive architecture for agents with emotionally influenced behaviors, called COGNITIVA, to maintain behaviors control without giving up the richness provided by emotions. This architecture, together with a progressive specification process for its application, have been used successfully to model 3D intelligent virtual agents.

Steve meets jack: The integration of an intelligent tutor and a virtual environment with planning capabilities

In this paper, we describe how we have integrated Steve, an intelligent tutor based on Soar, and HeSPI, a human simulation tool for planning and simulating maintenance tasks in nuclear power plants. The objectives of this integration were to test Steve’s flexibility to be used in different applications and environments and to extend HeSPI to use it as a virtual environment for training. We discuss the problems encountered and the solutions we have designed to solve them.

Applying a student modeling with non-monotonic diagnosis to Intelligent Virtual Environment for Training/Instruction

We present a student modeling approach that has been designed to be part of an Intelligent Virtual Environment for Training and/or Instruction (IVET). In order to provide the proper tutoring to a student, an IVET needs to keep and update dynamically a student model taking into account the students behaviour in the Virtual Environment. For that purpose, the proposed student model employs a student ontology, a pedagogic diagnosis module and a Conflict Solver module. The goal of the pedagogic diagnosis module is to infer which learning objectives have been acquired or not by the student. Nevertheless, the diagnosis process can be complicated by the fact that while learning the student will not only acquire new knowledge, but he/she may also forget some previously acquired knowledge, or he/she may have some oversights that could mislead the tutor about the true state of the students knowledge. All of these situations will lead to contradictions in the student model that must be solved so that the diagnosis can continue. Thus, our approach consists in applying diagnosis rules until a contradiction arises. At that moment, a conflict solver module is responsible of classifying and solving the contradiction. Next, the student ontology is updated according to the resolution adopted by the Conflict Solver and the diagnosis can continue. This paper mainly focuses on the design of the proper mechanisms of the student model to deal with the non monotonic nature of the pedagogic diagnosis.

A Human Based Perception Model for Cooperative Intelligent Virtual Agents

Interactive virtual worlds provide a powerful medium for experimental learning and entertainment. Nowadays, virtual environments often incorporate human-like embodied virtual agents with varying degrees of intelligence, getting what we call Intelligent Virtual Agents (IVAs). Collaboration between agents can be very important to reach aware of what is surrounding each agent each and every moment. This paper tries to find how to endow IVAs with a human perceptual model based on the reinterpretation of one of the more successful awareness models for Computer Supported Co-operative Work (CSCW).

Modelling the Sensory Abilities of Intelligent Virtual Agents

An important property of Intelligent Virtual Agents (IVAs) is their capability to acquire/perceive information from their environment. Bearing in mind some studies on situational awareness – where sensitive perception can be understood as the first level of awareness – and taking into account one of the most successful awareness models in Computer Supported Cooperative Work (CSCW) – the Spatial Model of Interaction (SMI), we have developed a human-like perceptual model for IVAs. This perceptual model extends and reinterprets the key concepts of the SMI and also introduces some factors typical from human being perception with the aim of making perception, in this kind of systems, more human-like.

Semantic Verification of Rule-Based Systems with Arithmetic Constraints

The aim of this paper is to show a method that is able to detect a particular class of semantic inconsistencies in a rule-based system (RBS). A semantic inconsistency is defined by an integrity constraint. A RBS verified by this method contains a set of production rules, and each production rule comprises a list of arithmetic constraints in its antecedent and a list of actions in its consequent. An arithmetic constraint is a linear inequality defined in the real domain that includes attributes, and an action is an assignment that changes an attribute value. As rules are allowed to include actions of this kind, the behaviour of the verified RBS is non-monotonic. The method is able to give a specification of all the initial fact bases (FB), and the rules from these initial FB that would have to be executed (in the right order) to cause an integrity constraint to be violated. So, the method builds an ATMS-like theory. Moreover, the treatment of arithmetic constraints is inspired by constraint logic programming.

Introducing human-like hearing perception in intelligent virtual agents

Although, at this moment, there are not many researches on perceptual models for Intelligent Virtual Agents, the few that exist are more focused on visual than on hearing perception. This paper describes the work that the Universidad Politicnica de Madrid, in collaboration with the University of Nottingham, is carrying on, with the aim of endowing Intelligent Virtual Agents with a synthetic model of human-like hearing perception. We have based the design and development of this model on Endsley studies about situational awareness [10,11], where perception can be understood as the first level of awareness. This perceptual model also extends and reinterprets the key concepts introduced by a CSCW model of awareness known as the Spatial Model of Interaction [4]. In this paper, we give an overview of those studies related to our work and we describe how we have achieved our purposes: selecting an agent architecture; re-defining and reinterpreting the set of key concepts introduced by the Spatial Model of Interaction; and analysing those factors that make the auditory perceptual model more realistic. We also expose how a mathematical function can describe the agents clarity of perception and how this model of perception has been implemented and evaluated.

An emotional architecture for virtual characters

This paper presents the mechanisms proposed by a generic cognitive architecture for virtual characters with emotional influenced behaviors, called cognitiva, to maintain behavior control at will without giving up the richness provided by emotions. This architecture, together with a progressive specification process for its application, have been used successfully to model 3D intelligent virtual actors for virtual storytelling.