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Sumbul Jahan. Recommender Systems. This world is an over-crowded place. They all want to get our attention. But we need a few of them!. Something which is popular. Something which is of our interest. Something which is liked by people of our community. What we are looking for?.
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SumbulJahan Recommender Systems
Something which is popular. Something which is of our interest. Something which is liked by people of our community. What we are looking for?
An information filtering technology, commonly used on e-commerceWeb sites that uses a collaborative filtering to present information on items and products that are likely to be of interest to the reader. What is recommender system http://citationmachine.net/index2.php?reqstyleid=2
What can be recommended • Advertising messages • Investment choice • Restaurants • Cafes • Music tracks • Movies • TV programs • Books • Stores • Tags • News articles • Future friends • Research papers • Citations • Courses • Articles • Supermarket goods • Products/Services http://www.slideshare.net/T212/recommender-systems-1311490
Content Based Collaborative Filtering Knowledge Based Types of recommender system http://www.umiacs.umd.edu/~jimmylin/INFM700-2008 Spring/presentations/recommender_systems.ppt.
Recommend items based on user’s past preferences. Items/content usually denoted by keywords. Matching “user preferences” with “item characteristics” … works for textual information. User profile is the key. Content Based
Not all content is well represented by keywords, e.g. images. No profile is available for new users. Unrated items are not shown. Users with thousands of purchases is a problem. Content Based - Limitations
Recommend items based on ratings of users sharing similar interests. Collaborative filtering systems can produce personal recommendations by computing the similarity between your preference and the one of other people. More users, more ratings: better results. Collaborative Filtering http://pehttp://pespmc1.vub.ac.be/collfilt.html
Different users might use different scales. Possible solution: weighted ratings, i.e. deviations from average rating. Finding similar users/user group is not very easy. No preference is available of new users. No rating is available of new items. Collaborative filtering - limitations
Knowledge of user is linked to knowledge of products. • Conversational interaction used to establish current user preferences i.e. “more like this”, “less like that”, “none of those” … • No user profiles maintained, preferences drawn through manual interaction Knowledge Based
Netflix • 2/3 rented movies are from recommendation. Usage http://www.shttp://pespmc1.vub.ac.be/collfilt.html lideshare.net/T212/recommender-systems-1311490
Google News • More than 38% click-through are due to recommendation. Usage http://www.slideshare.net/T212/recommender-systems-1311490
Amazon • 35% sales are from recommendation. Usage http://www.slideshare.net/T212/recommender-systems-1311490