Managing Weighted Preferences with Constraints in Interactive Applications Bandar Mohammed 1 , Malek Mouhoub 1 , Eisa Alanazi 2 and Samira Sadaoui 1 1 Department of Computer Science, University of Regina, Regina, SK, Canada 2 Department of Computer Science, Umm Al-Qura University, Mecca, Saudi Arabia Keywords: Preference Reasoning, Constrained Optimization, CP-nets, Weighted CP-nets. Abstract: Developing intelligent and interactive systems with visual user interfaces is essential for any website and mobile device. In this study, we propose a new web-based shopping system to elicit buyer’s requirements and preferences and to provide a set of suggestions accordingly. This process is achieved by first representing the elicited information through graphical models and then solving the underlying constrained problem. More precisely, we have used the Weighted CP-nets (WCP-net) graphical model to allow the user to express fine- grained preferences on the product attributes and their values in a quantitative or a conditional qualitative form. The latter has been extended in this paper to include constraints between attributes. A backtrack search algorithm is then performed to solve the constrained WCP-net and to return a set of Pareto optimal solutions satisfying all the constraints and maximizing all the preferences. 1 INTRODUCTION Nowadays, client preferences, such as web services (Santhanam et al., 2008; Brafman and Domshlak, 2009a), play a key role in customized artificial in- telligence applications. Several online websites in- clude some communication with customers to be able to comprehend and respond to their needs. When a client is enthusiastic about purchasing a new product, he will access the web to search for it. However, ex- isting shopping sites offering clients new goods are still problematic. Clients may not be pleased if these sites are difficult to use as they do not want to deal with complications or spend too much time brows- ing through the sites. Corporations may not see this as a serious issue when designing shopping websites that are not user friendly. Additionally, the results produced by these websites do not usually meet the specifications of clients. To be successful, these ap- plications should improve the consumer interaction. Increasing the satisfaction of users can be achieved by assist them in eliciting their preferences and re- quirements as done in matchmaking systems (Jiang and Sadaoui, 2012) and online auctions (Sadaoui and Shil, 2016). Furthermore, several of these websites are available in a restricted environment. While ex- pressing his preferences for a laptop for example, the customer cannot select parts that are not compatible with each other. Hence, we should consider a sce- nario where both preferences and constraints co-exist together (Sadaoui and Shil, 2016). This has motivated us to develop an interactive shopping application that maximizes the user’s desires while satisfying some re- quirements. This application is based on the Weighted CP-nets (WCP-net) graphical model that we extend to include constraints between attributes. A backtrack search algorithm is then performed to solve the con- strained WCP-net and to return a set of Pareto optimal solutions satisfying all the constraints and maximiz- ing all the preferences. The rest of the paper is structured as follows. The following section provides a brief background about preferences and related graphical models as well as constraint satisfaction. Section 3 presents the ex- tended model Weighted CP-nets. Section 4 describes our interactive shopping system based on Weighted CP-nets. Finally, Section 5 lists concluding remarks and future works. 2 BACKGROUND Preference reasoning is an important subject in the area of artificial intelligence, computer science and fi- nances (Walsh, 2007; Brafman and Domshlak, 2009b; Mohammed, B., Mouhoub, M., Alanazi, E. and Sadaoui, S. Managing Weighted Preferences with Constraints in Interactive Applications. DOI: 10.5220/0006902002550260 In Proceedings of the 15th International Conference on Informatics in Control, Automation and Robotics (ICINCO 2018) - Volume 1, pages 255-260 ISBN: 978-989-758-321-6 Copyright © 2018 by SCITEPRESS – Science and Technology Publications, Lda. All rights reserved 255