Categories of Inference in a Multi-Faceted, Educational, Knowledge-based Recommender System John W. Coffey The Institute for Human and Machine Cognition and Department of Computer Science The University of West Florida Pensacola FL 32514 USA jcoffey@uwf.edu Abstract Knowledge-based recommender systems comprise one category of user-modeling system that can draw inferences from user models. This brief paper contains a global description of a multi-faceted, educational, knowledge-based recommender system, including a basic set of descriptors that the model contains, a taxonomy of inferences that might be made over such models, and a listing of literature that is relevant to educational recommender systems. This section contains a description of a framework for an educational, knowledge-based recommender system. The following sections contain descriptions of the types of student attributes that are modeled in such a system, and a taxonomy of inference rule types that might be formulated as part of the recommendation process. Attributes of a Student Model Introduction Student modeling is an endeavor within the broader realm of user modeling. The goal of student modeling is to create representations of various attributes of students that can be leveraged through computerized means to enhance the educational process. Work in this area has traditionally been geared toward individual students. However, the endeavor holds the promise of supporting customized learning systems tailored to individuals or collaborating groups through the recommendation of learning resources, or through recommendations regarding the constitution of the groups themselves to instructors. The current work describes a framework for knowledge-based recommender systems that pertains to collaborating groups as well as individuals. A prototype built with SWI Prolog (for simplicity and efficiency of prototyping) that implements the framework, has been created. The rest of this paper describes the framework, which includes attributes that would be captured and represented in a student model, and a taxonomy of inference types that might be made over the models. The taxonomy of inference types includes people-to-people relationships, resource-to-resource relationships, and people-to resource-relationships. The bibliography that is provided contains references that are relevant to this work. Copyright © 2004, American Association Intelligence (www.aaai.org). All rights reserved A Framework for an Educational Recommender System for Artificial The literature contains descriptions of a wide range of attributes of students that might be included in a student model. Student attributes pertaining to academic performance and attainment would clearly be part of a student modeling system. A variety of means of characterizing student attainment have been proposed. Assessment of performance in an individual topic can be characterized by a number of dimensions. For example, attainment in a topic in a course on Data Structures might be characterized by dimensions including the theory behind the data structure (computational complexity of operations), design with the structure, programming various operations on the data structure, etc. Other types of academic attainment measures might capture attributes such as reading level, math ability, etc. Demographic information such as age, gender, and location are potentially of use. Learning style information can be used to develop teams of students with similar or complementary approaches to problem-solving and learning. Interest inventories can be of utility. Interest inventories may pertain to topic areas of interest and to specific types of activities a student prefers. For instance, some students might favor behind-thescenes work such as programming; while others might prefer interpersonal work such as preparation and presentation of documents and communications, and more general planning. A Taxonomy of Inference Categories Inference over student models can be in service of a variety of goals. The proposed framework is comprised of three general categories of inference: • People-to-people • Resource-to-resource • People-to-resource People-to-people queries are used by students themselves in order to identify potential collaborators, or by instructors to form collaborating groups. Resource-to-resource queries are used to assemble packages of resources to address specific learning objectives. People-to-resource queries are used to match collaborating teams to resource packages. Resource-to-resource queries utilize attributes of resources in order to build aggregations of resources directed toward an individual or group. Basic attributes of resources include content area (to what topic or topics does the resource pertain?), the basic type of document: theoretical, applied, case study, etc., intended audience: introductory, intermediate or advanced, reading level, and chronology of document formation (to address the evolution of thought in the area). Descriptors are used to create sequences of resources, for instance suggesting that a theoretical description be viewed first, followed by a simple case study that makes sense within the context of the theory, and then a more complex case study that requires generalization of the theory. People-to-resource queries identify interest or remediation items for the individuals or for groups that are identified in the people-to-people results. The goal is to build tailored packages of resources that might be of utility to the individual or group. Conclusions This work describes a basic, global framework for student modeling in service of an educational, knowledge-based recommender system. One of the main motivations for this work is the anticipation of the sorts of inferences that might be performed in courses offered at a distance, utilizing multi-faceted models of students and semantically characterized resources. It seems clear that the ability of instructors to gain a better understanding of their students would be particularly valuable in distance learning settings. Although this brief description of the current work does not afford room for examples of queries that have been formulated, it is worth noting that the rules form triples that are easily converted into a representation such as RDF. Implementation of this framework in the context of a learning management system for Web-based course offerings holds potential to address many deficiencies of current distance-learning environments. The combination of multi-faceted student models with the Semantic Web holds the promise to usher in a new era in distance learning environments. Relevant Literature Barker, T., Jones, S., Britton, C., and Messer, D. 2002. The Use of Co-operative Student Model of Learner Characteristics to Configure a Multimedia Application. User Modeling and User-Adapted Interaction. 12:207-241. Bianchi-Berthouze, N., and Lisetti, C.L. 2002. Modeling Multimodal Expression of User's Affective Subjective Experience. User Modeling and UserAdapted Interaction. 12:49-84, Brusilovsky, P. 1996. Methods and Techniques of Adaptive Hypermedia In P. Brusilovsky and J. Vassileva, eds. User Modeling and User-Adapted Interaction. Special issue on Adaptive Hypertext and Hypermedia. 6(2-3):87-129. Bull, S. Brna, P., and Pain, H. 1995. Extending the Scope of the Student Model. User Modeling and User-adapted Interaction. 5(1): 45-65. Burke, R. 2002. Hybrid recommender systems: Survey and Experiments. User Modeling and UserAdapted Interaction. 12:331-370. Calvi, L., and Cristea, A. 2002. Towards Generic Adaptive Systems: Analysis of a Case Study. Lecture Notes in Computer Science, vol. 2347: De Bra, P.; Brusilovsky, P.; Conejo, R., eds. Springer-Verlag. Conlan, O., Wade, V., Bruen, C., and Gargan, M. 2002. Multi-model, Metadata Driven Approach to Adaptive Hypermedia Services for Personalized ELearning, Lecture Notes in Computer Science, vol. 2347: De Bra, P.; Brusilovsky, P.; Conejo, R., eds. Springer-Verlag. De Bra, P., and Ruiter, J. 2002. AHA! Adaptive Hypermedia for All. Proceedings of WebNet 2001, World Conference on the WWW and Internet. October 23-27, 2001, Orlando, FL. 262-268. Finin, T., and Drager, D. 1986. GUMS: A General User Modeling System. In Proceedings of the 1986 Canadian Society for Computational Studies of Intelligence (CSCSI-86). 24-30. Montreal, Canada, May 21-23. Kurhila, J., Miettinen, M., Nokelaimen, P., and Tirri, H. 2002. EDUCO - A Collaborative Learning Environment Based on Social Navigation. Lecture Notes in Computer Science, vol. 2347: De Bra, P.; Brusilovsky, P.; Conejo, R., eds. Springer-Verlag. Rich, E. 1979. User Modeling via Stereotypes. Cognitive Science 3:329-354.