Question: What is the limitation of the Collaborative Filtering method?
Evidence: Today, Internet is one of the widest available media worldwide. It has essentially become a huge hit of data that has the potential to serve many information centric applications in our life. Recommendation system takes an essential part of many internet services and online applications, including applications like social-networking and recommendation of products (films, music, articles,..i.e.). Recommendation techniques have been used by the most known companies such as Amazon, Netflix and eBay to recommend releated items or products by estimating the probable preferences of customers. These techniques are profitable to both service provider and user. According to pervious works, two popular approaches for building recommendation systems can be categorized as content-based (CB), collaborative filtering (CF).
Content-based (CB) recommending is adopted for recommendation systems model widely, which takes advantage of the property of items to create features and characteristics to coordinate user profiles. It can be relied on the properties of the items that each user likes to discover what else the user may like. One major issue of CB filtering method is that the recommendation system is required to gain an understanding of user preferences for some sorts of items and deploy these for other sorts of items.
Nevertheless CF has two widely known problems which are sparsity and cold start (CS). In the rating matrix, The percentage of elements which get values is small. Even it is possible that CF considers only a few rating for popular items. For instance, upon a considerable Netflix rating dataset which is provided for Netflix Prize competition, there are about 100 milion ratings for about 18,000 movies that are given by 480,000 users. The percentage of rating matrix elements which are received ratings is 1. With a sparse ranking matrix it is very challenging topic to make an effective recommendation, depending on estimation of the relationship between items and users. CS problem is another widely known issue for CF approach, which can occur on new users or items. In terms of achieving an effective recommendation, CF approach requires either ratings on an item or a large number of ratings from a user.
Recently, researchers proposed various methods based on probabilistic topic modeling methods BIBREF0. LDA is a generative probabilistic model broadly used in the information retrieval field. Researchers have used topic modeling methods based on LDA for building recommendation systems in various subjects, including app recommendation BIBREF1, BIBREF2, BIBREF3, BIBREF4, BIBREF5, event recommendationBIBREF6, BIBREF7, BIBREF8, BIBREF9, BIBREF10, BIBREF11, BIBREF12, BIBREF13, BIBREF14, BIBREF15, hashtag recommendation BIBREF16, BIBREF17, BIBREF18, BIBREF19, BIBREF20, BIBREF21, BIBREF22, BIBREF23, BIBREF24, BIBREF25, BIBREF26, BIBREF27, BIBREF28, BIBREF29, BIBREF30, BIBREF31, BIBREF32, BIBREF33, BIBREF34, BIBREF35, BIBREF36, social networks and media BIBREF37, BIBREF38, BIBREF6, BIBREF9, BIBREF39, BIBREF40, BIBREF41. In this paper, We present a taxonomy of recommendation systems applications based on topic modeling (LDA) of the recent research and evaluate ISWC and WWW publications in computer science between 2013 to 2017 from DBLP dataset.
Nevertheless CF has two widely known problems which are sparsity and cold start (CS).
Answer: CF has two widely known problems which are sparsity and cold start (CS).