A Collaborative Filtering Algorithm with Phased Forecast.
ABSTRACT Collaborative filtering (CF) algorithms predict interests of an active user in order to deal with the overload of information.
Usually, changes of her interests have been ignored in traditional algorithms, which take user’s interest as static data and
product rating in different phase with same weight. So when users’ interests have changed as time goes on, unneeded items
may be recommended. In order to solve above problem, we propose a new item-based collaborative filtering algorithm in this
paper. In this algorithm, named PFCF, we firstly divide users’ rating history into several periods, then users’ interests
distributing in these periods are analyzed by a phrased forecast method, which is used to find user’s different type interests.
The proposed algorithm is strictly tested on the MovieLens data set. The experimental results show its good precision against
other traditional item-based collaborative filtering algorithms.
- SourceAvailable from: John Tsibouklis
Conference Paper: Item-based collaborative filtering recommendation algorithmus[Show abstract] [Hide abstract]
ABSTRACT: Recommender systems apply knowledge discovery techniques to the problem of making personalized recom- mendations for information, products or services during a live interaction. These systems, especially the k-nearest neighbor collaborative filtering based ones, are achieving widespread success on the Web. The tremendous growth in the amount of available information and the number of visitors to Web sites in recent years poses some key challenges for recommender systems. These are: producing high quality recommendations, performing many recommendations per second for millions of users and items and achieving high coverage in the face of data sparsity. In traditional collaborative filtering systems the amount of work increases with the number of participants in the system. New recommender system technologies are needed that can quickly produce high quality recommendations, even for very large-scale problems. To address these issues we have explored item-based collaborative filtering techniques. Item- based techniques first analyze the user-item matrix to identify relationships between different items, and then use these relationships to indirectly compute recommendations for users. In this paper we analyze different item-based recommendation generation algorithms. We look into different techniques for computing item-item similarities (e.g., item-item correlation vs. cosine similarities between item vec- tors) and different techniques for obtaining recommendations from them (e.g., weighted sum vs. regression model). Finally, we experimentally evaluate our results and compare them to the basic k-nearest neighbor approach. Our experiments suggest that item-based algorithms provide dramatically better performance than user-based algorithms, while at the same time providing better quality than the best available user-based algorithms.01/2001
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ABSTRACT: This article discusses the challenges involved in creating a collaborative filtering system for Usenet news. The public trial of GroupLens invited users from over a dozen newsgroups selected to represent a cross-section of Usenet (listed in Table 1) to apply our news reader software to enter ratings and receive predictions (we provided GroupLens-adapted versions of Gnus, xrn, and tin). Over a seven-week trial starting February 8, 1996, we registered 250 users who submitted a total of 47,569 ratings and received over 600,000 predictions for 22,862 different articles. These users were volunteers who saw our announcement postings or our Web page. They downloaded specially modified news browsers that accepted ratings and displayed predictions on a 1--5 scale where 1 was described as "this item is really bad! a waste of net.bandwidth" and 5 as "this article is great, I would like to see more like it." For privacy reasons, users were known to us only by pseudonyms. Qualitative results are therefore the compilation of feedback from the GroupLens mailing list and private email rather than a comprehensive survey. In  we present a more detailed summary of the trial results, along with comparisons with noncollaborative approaches to managing Usenet news.02/2000;
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ABSTRACT: Recommendation algorithms are best known for their use on e-commerce Web sites, where they use input about a customer's interests to generate a list of recommended items. Many applications use only the items that customers purchase and explicitly rate to represent their interests, but they can also use other attributes, including items viewed, demographic data, subject interests, and favorite artists. At Amazon.com, we use recommendation algorithms to personalize the online store for each customer. The store radically changes based on customer interests, showing programming titles to a software engineer and baby toys to a new mother. There are three common approaches to solving the recommendation problem: traditional collaborative filtering, cluster models, and search-based methods. Here, we compare these methods with our algorithm, which we call item-to-item collaborative filtering. Unlike traditional collaborative filtering, our algorithm's online computation scales independently of the number of customers and number of items in the product catalog. Our algorithm produces recommendations in real-time, scales to massive data sets, and generates high quality recommendations.IEEE Internet Computing 02/2003; · 2.00 Impact Factor