User-Centric Evaluation of Recommender Systems in Social Learning Platforms: Accuracy is Just the Tip of the Iceberg

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Bibliographic Details
Title: User-Centric Evaluation of Recommender Systems in Social Learning Platforms: Accuracy is Just the Tip of the Iceberg
Language: English
Authors: Fazeli, Soude (ORCID 0000-0003-1250-994X), Drachsler, Hendrik, Bitter-Rijpkema, Marlies, Brouns, Francis (ORCID 0000-0002-6240-2684), Brouns, Wim van der Vegt, Sloep, Peter B.
Source: IEEE Transactions on Learning Technologies. Jul-Sep 2018 11(3):294-306.
Availability: Institute of Electrical and Electronics Engineers, Inc. 445 Hoes Lane, Piscataway, NJ 08854. Tel: 732-981-0060; Web site: http://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=4620076
Peer Reviewed: Y
Page Count: 13
Publication Date: 2018
Document Type: Journal Articles
Reports - Research
Tests/Questionnaires
Descriptors: Evaluation, Socialization, Accuracy, Prediction, Neighborhoods, Memory, Mathematics, Foreign Countries, User Satisfaction (Information), Information Systems
Geographic Terms: Greece, Netherlands, Romania, United Kingdom, Cyprus, Germany, Serbia, Bulgaria, Croatia, Estonia, Ireland, Lithuania, Poland, Portugal, Spain
DOI: 10.1109/TLT.2017.2732349
ISSN: 1939-1382
Abstract: Recommender systems provide users with content they might be interested in. Conventionally, recommender systems are evaluated mostly by using prediction accuracy metrics only. But, the ultimate goal of a recommender system is to increase user satisfaction. Therefore, evaluations that measure user satisfaction should also be performed before deploying a recommender system in a real target environment. Such evaluations are laborious and complicated compared to the traditional, data-centric evaluations, though. In this study, we carried out a user-centric evaluation of state-of-the-art recommender systems as well as a graph-based approach in the ecologically valid setting of an authentic social learning platform. We also conducted a data-centric evaluation on the same data to investigate the added value of user-centric evaluations and how user satisfaction of a recommender system is related to its performance in terms of accuracy metrics. Our findings suggest that user-centric evaluation results are not necessarily in line with data-centric evaluation results. We conclude that the traditional evaluation of recommender systems in terms of prediction accuracy only does not suffice to judge performance of recommender systems on the user side. Moreover, the user-centric evaluation provides valuable insights in how candidate algorithms perform on each of the five quality metrics for recommendations: usefulness, accuracy, novelty, diversity, and serendipity.
Abstractor: As Provided
Number of References: 40
Entry Date: 2018
Accession Number: EJ1192608
Database: ERIC
Description
Abstract:Recommender systems provide users with content they might be interested in. Conventionally, recommender systems are evaluated mostly by using prediction accuracy metrics only. But, the ultimate goal of a recommender system is to increase user satisfaction. Therefore, evaluations that measure user satisfaction should also be performed before deploying a recommender system in a real target environment. Such evaluations are laborious and complicated compared to the traditional, data-centric evaluations, though. In this study, we carried out a user-centric evaluation of state-of-the-art recommender systems as well as a graph-based approach in the ecologically valid setting of an authentic social learning platform. We also conducted a data-centric evaluation on the same data to investigate the added value of user-centric evaluations and how user satisfaction of a recommender system is related to its performance in terms of accuracy metrics. Our findings suggest that user-centric evaluation results are not necessarily in line with data-centric evaluation results. We conclude that the traditional evaluation of recommender systems in terms of prediction accuracy only does not suffice to judge performance of recommender systems on the user side. Moreover, the user-centric evaluation provides valuable insights in how candidate algorithms perform on each of the five quality metrics for recommendations: usefulness, accuracy, novelty, diversity, and serendipity.
ISSN:1939-1382
DOI:10.1109/TLT.2017.2732349