北京大学：《信息检索》课程PPT课件讲稿（自然语言处理）04 Recommendation System

NC&IS Recommendation System The CCF Advanced Disciplines Lectures 彭波 pb@net.pku.edu.cn 北京大学信息科学技术学院 6/27/2010

Recommendation System The CCF Advanced Disciplines Lectures 彭波 pb@net.pku.edu.cn 北京大学信息科学技术学院 6/27/2010

Outline What is Recommendation System? Nearest-Neighbor Collaborative Filtering Algorithm ■Evaluation Recommendation Systems

Outline ◼ What is Recommendation System? ◼ Nearest-Neighbor Collaborative Filtering Algorithm ◼ Evaluation ◼ Recommendation Systems

NC&IS What is Recommendation System?

What is Recommendation System?

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The Problem 分类 检索 还有什么 有效的手段？

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Recommendation

件⑧) 编辑)查看)收寐4)快捷组@)选项@)工具红)窗口W)帮助D :工 · 令·金·8·日~个☆4回9·目图国日☒·▣回·☒ http:/∥m,amazon.com//Modern--Information-Retrieval-Ricardo-Baeza-Yates//y日、搜索月 ￥⊙·☑ Ne,moder:《现.Amazo,, Amazo.:北京Item-,Amazo., 回过回1aazo可i。回你回Co回Do. Co...if:bo. Click me for amazoncom Gpp0el时0 .com Books You AccountI月Cat I Your sts日IHep1 I Magazines 93 Textbooks Search Books GO ©Find Gifts AO Web Search Join Amazon Prime and ship Two-Day for free and Overnight for $3.99 gn up for Amazon Prime today Modern Information Retrieval (Paperback) Modern by Ricardo Baeza-Yates,Berthier Ribeiro-Neto Quantity:1 Information ☆★★★★(8 customer reviey2 Retrieval Add to Shopping Cart or List Price:$56-80 Sign in to turn on 1-Click Price:$46.58&this item ships for FREE with Super Saver ordering. Shipping.Details You Save:$10.22(18%) More Buying Choices Availability:Usually ships within 4 to 6 weeks.Ships from and sold by Amazon.com. 15 used new from $38.94 Have one to sell?Sell yours here 15 used new available from $38.94 See larger image Add to Wish List Share your own customer images lisher:learn how customers can search inside this book Add to Shopping List re you the publisher or author?Learn Add to Wedding Registry how Amazon can help you make this book an eBooki Add to Baby Registry

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Personalized Recommendation

Everyday Examples of Recommendation Systems... Bestseller lists ■Top40 music lists The "recent returns"shelf at the library ■“Read any good books lately?? Customers who bought this also bought... Common insight:personal tastes are correlated: .If Marry and Bob both like X and Marry likes Y then Bob is more likely to like Y especially(perhaps)if Bob knows Marry

Everyday Examples of Recommendation Systems… ◼ Bestseller lists ◼ Top 40 music lists ◼ The “recent returns” shelf at the library ◼ “Read any good books lately?” ◼ Customers who bought this also bought… ◼ .... Common insight: personal tastes are correlated: •If Marry and Bob both like X and Marry likes Y then Bob is more likely to like Y •especially (perhaps) if Bob knows Marry

Sample Applications Ecommerce Product recommendations-amazon Corporate Intranets Recommendation,finding domain experts,.. ■Digital Libraries Finding pages/books people will like Medical Applications Matching patients to doctors,clinical trials,... Customer Relationship Management Matching customer problems to internal experts

Sample Applications ◼ Ecommerce ◼ Product recommendations - amazon ◼ Corporate Intranets ◼ Recommendation, finding domain experts, … ◼ Digital Libraries ◼ Finding pages/books people will like ◼ Medical Applications ◼ Matching patients to doctors, clinical trials, … ◼ Customer Relationship Management ◼ Matching customer problems to internal experts