Fast ALS-based tensor factorization for context-aware recommendation from implicit feedback

Albeit, the implicit feedback based recommendation problem - when only the user history is available but there are no ratings - is the most typical setting in real-world applications, it is much less researched than the explicit feedback case. State-of-the-art algorithms that are efficient on the explicit case cannot be straightforwardly transformed to the implicit case if scalability should be maintained. There are few if any implicit feedback benchmark datasets, therefore new ideas are usually experimented on explicit benchmarks. In this paper, we propose a generic context-aware implicit feedback recommender algorithm, coined iTALS. iTALS apply a fast, ALS-based tensor factorization learning method that scales linearly with the number of non-zero elements in the tensor. The method also allows us to incorporate diverse context information into the model while maintaining its computational efficiency. In particular, we present two such context-aware implementation variants of iTALS. The first incorporates seasonality and enables to distinguish user behavior in different time intervals. The other views the user history as sequential information and has the ability to recognize usage pattern typical to certain group of items, e.g. to automatically tell apart product types or categories that are typically purchased repetitively (collectibles, grocery goods) or once (household appliances). Experiments performed on three implicit datasets (two proprietary ones and an implicit variant of the Netflix dataset) show that by integrating context-aware information with our factorization framework into the state-of-the-art implicit recommender algorithm the recommendation quality improves significantly.Comment: Accepted for ECML/PKDD 2012, presented on 25th September 2012, Bristol, U

Context-aware LDA: Balancing Relevance and Diversity in TV Content Recommenders

In the vast and expanding ocean of digital content, users are hardly satisfied with recommended programs solely based on static user patterns and common statistics. Therefore, there is growing interest in recommendation approaches that aim to provide a certain level of diversity, besides precision and ranking. Context-awareness, which is an effective way to express dynamics and adaptivity, is widely used in recom-mender systems to set a proper balance between ranking and diversity. In light of these observations, we introduce a recommender with a context-aware probabilistic graphi-cal model and apply it to a campus-wide TV content de-livery system named “Vision”. Within this recommender, selection criteria of candidate fields and contextual factors are designed and users’ dependencies on their personal pref-erence or the aforementioned contextual influences can be distinguished. Most importantly, as to the role of balanc-ing relevance and diversity, final experiment results prove that context-aware LDA can evidently outperform other al-gorithms on both metrics. Thus this scalable model can be flexibly used for different recommendation purposes

Selection of Software Product Line Implementation Components Using Recommender Systems: An Application to Wordpress

In software products line (SPL), there may be features which can be implemented by different components, which means there are several implementations for the same feature. In this context, the selection of the best components set to implement a given configuration is a challenging task due to the high number of combinations and options which could be selected. In certain scenarios, it is possible to find information associated with the components which could help in this selection task, such as user ratings. In this paper, we introduce a component-based recommender system, called (REcommender System that suggests implementation Components from selecteD fEatures), which uses information associated with the implementation components to make recommendations in the domain of the SPL configuration. We also provide a RESDEC reference implementation that supports collaborative-based and content-based filtering algorithms to recommend (i.e., implementation components) regarding WordPress-based websites configuration. The empirical results, on a knowledge base with 680 plugins and 187 000 ratings by 116 000 users, show promising results. Concretely, this indicates that it is possible to guide the user throughout the implementation components selection with a margin of error smaller than 13% according to our evaluation.Ministerio de Economía y Competitividad RTI2018-101204-B-C22Ministerio de Economía y Competitividad TIN2014-55894-C2-1-RMinisterio de Economía y Competitividad TIN2017-88209-C2-2-RMinisterio de Economía, Industria y Competitividad MCIU-AEI TIN2017-90644-RED

Multi-dimension Tensor Factorization Collaborative Filtering Recommendation for Academic Profiles

The choice of academic itineraries and/or optional subjects to attend is not usually an easy decision since, in most cases, students lack the information, maturity, and knowledge required to make right decisions. This paper evaluates the support of Collaborative Systems for helping and guiding students in this decision-making process, considering the behavior and impact of these systems on the use of data different from the formal information the students usually use. For this purpose, the research applied the clustering based Multi-dimension Tensor Factorization approach to build a recommendation system and confirm that the increment in tensors improves the recommendation accuracy. As a result, this approach permits the user to take advantage of the contextual information to reduce the sparsity issue and increase the recommendation accuracy

An Ontology-Based Recommender System with an Application to the Star Trek Television Franchise

Collaborative filtering based recommender systems have proven to be extremely successful in settings where user preference data on items is abundant. However, collaborative filtering algorithms are hindered by their weakness against the item cold-start problem and general lack of interpretability. Ontology-based recommender systems exploit hierarchical organizations of users and items to enhance browsing, recommendation, and profile construction. While ontology-based approaches address the shortcomings of their collaborative filtering counterparts, ontological organizations of items can be difficult to obtain for items that mostly belong to the same category (e.g., television series episodes). In this paper, we present an ontology-based recommender system that integrates the knowledge represented in a large ontology of literary themes to produce fiction content recommendations. The main novelty of this work is an ontology-based method for computing similarities between items and its integration with the classical Item-KNN (K-nearest neighbors) algorithm. As a study case, we evaluated the proposed method against other approaches by performing the classical rating prediction task on a collection of Star Trek television series episodes in an item cold-start scenario. This transverse evaluation provides insights into the utility of different information resources and methods for the initial stages of recommender system development. We found our proposed method to be a convenient alternative to collaborative filtering approaches for collections of mostly similar items, particularly when other content-based approaches are not applicable or otherwise unavailable. Aside from the new methods, this paper contributes a testbed for future research and an online framework to collaboratively extend the ontology of literary themes to cover other narrative content.Comment: 25 pages, 6 figures, 5 tables, minor revision

Розробка та дослідження моделей та програмних рішень для рекомендаційної системи вибору товарів масового вжитку

There have been proposed investigation of the problem of creating recommendations with technical description for building the Recommender System of consumer goods with help of modern algorithms, approaches, principles and contains the investigation of the most popular methods. It was defined, that the deployment of Recommender Systems is one of the rapidly developing areas for improving applied information technolog ies, tools for automatic generating offers service based on the investigation of the personal needs and profile of customers. It was investigated, that such systems have started to play a very important role in the fast growing Internet, as they help users to navigate in a large amount of information, because users are not able to analyze a large amount of information, because it is very difficult and takes a lot of time and effort, but due to such systems, namely Recommender Systems that are able to filter a large amount of information, and provide for users the information and recommendations their likes the problem can be solved and instead of providing the static information, when users search and, perhaps, buy products, Recommender Systems increase the degree of interactivity to expand the opportunities provided to the user. It was defined, that Recommendation systems form recommendations independently for each specific user based on past purchases and searches, and also on the basis of the behavior of other users with help of recommendation services, which collect different information about a person using several methods and at the same time all systems are shared. An overview of content-based, collaborative filtering and hybrid methods was performed. An overview of Alternating Least Squares and Singular Value Decomposition recommendation algorithms was performed. The design of the Recommender System of consumer goods software component was described. The main features of software implementation and programming tools for the system which is being developed were explained. The conclusions about the problems of Recommender Systems and the review of existing algorithms were made.Запропоновано дослідження проблеми створення рекомендацій, з технічним описом для побудови рекомендаційної системи для вибору товарів масового вжитку за допомогою сучасних алгоритмів, підходів, принципів і містить дослідження найбільш популярних методів. Було визначено, що впровадження рекомендаційних систем є однією з областей, які швидко розвиваються для вдосконалення прикладних інформаційних технологій, інструментів для автоматичного генерування пропозицій, заснованих на дослідженні особистих потреб і профілю клієнтів. Було досліджено, що такі системи почали грати дуже важливу роль в швидко зростаючому Інтернеті, оскільки вони допомагають користувачам орієнтуватися у великій кількості інформації, користувачі не можуть аналізувати великий обсяг інформації, адже це дуже складно і також вимагає багато часу і зусиль, але завдяки рекомендаційним системам, які можуть фільтрувати великий обсяг інформації і надавати користувачам інформацію і рекомендації, які їм подобаються, проблема може бути вирішена і замість надання статичної інформації, коли користувачі шукають, і можливо, купують продукти, такі системи збільшують ступінь інтерактивності для розширення можливостей, що надаються користувачеві. Було визначено, що рекомендаційні системи формують рекомендації самостійно для кожного конкретного користувача на основі минулих покупок і пошуків, а також на основі поведінки інших користувачів за допомогою служб рекомендацій, які збирають різну інформацію про людину, що використовує кілька методів, і в той же час всі системи є загальними. Було проведено огляд методів фільтрації на основі контенту, спільної фільтрації і гібридних методів. Було виконано огляд алгоритмів альтернативних найменших квадратів і сингулярного розкладання. Описана конструкція рекомендаційної системи програмного забезпечення для вибору товарів масового вжитку. Зроблено пояснення деяких можливостей програмної реалізації і інструментів програмування для розроблюваної системи. Зроблено висновки про проблеми рекомендаційних систем і огляд існуючих алгоритмів