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Personalized Query Classification. Bin Cao, Qiang Yang, Derek Hao Hu, et al. Computer Science and Engineering Hong Kong UST. Query Classification and Online Advertisement. QC as Machine Learning. Inspired by the KDDCUP’05 competition Classify a query into a ranked list of categories
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Personalized Query Classification Bin Cao, Qiang Yang, Derek Hao Hu, et al. Computer Science and Engineering Hong Kong UST
QC as Machine Learning Inspired by the KDDCUP’05 competition • Classify a query into a ranked list of categories • Queries are collected from real search engines • Target categories are organized in a tree with each node being a category
Our QC Demo • http://q2c.cs.ust.hk/q2c/
Personalization • The aim of Personalized Query Classification is to classify a user query Q to a ranked list of predefined categories for different users
PQC: Personalized Query Classification • classify a user query Q to a ranked list of categories for different users
Question:Can we personalize search without user registration info? • Profile based PQC • Context based PQC • Conclusion
Difficulties • Web Queries are • Short, sparse: “adi”, ”cs”, “ps” • Noisy: “contnt”, “gogle” • New words are emerging all the time: “windows7” • Training data are hard for human to label • Experts may have different understandings for the same ambiguous query • E.g. “Apple”, “Office”, etc.
Method 1: Profile Based • Profile (U) = { <Q, Search-Result, Clicked-URL>} in the past • Profile based Personalized Query Classification Michael Jordan -…. √ …. √ …. -…. √ …. √ …. -…. √ …. √ …. √ …. -…. √ …. √ …. -…. √ …. √ …. -…. √ …. √ …. -…. √ …. √ …. -…. √ …. √ …. -…. √ …. - …. √ …. √ …. - …. √ …. √ …. √ …. -…. √ …. - …. √ …. √ …. √ …. -…. √ …. √ …. -…. √ ….
Method 2: Context Based • Context = a session of user submitted queries Graphical Model Machine Learning UCB Michael Jordan
Outline • Introduction • Profile based PQC • Context based PQC • Conclusion
How to construct a user profile? • To achieve personalized query classification, under independence assumption • ACM KDDCUP 2005 Solution: estimating: p(q|c) • Focus: estimating p(u|c) for personalization • Difficulty: sparseness • Too many possible categories • Limited information for each user p(c|q,u) ∝ p(q|c)p(u|c)p(c)
Categorized Clickthrough Data:Too Few! Clickthrough Data Search Engines
Collaborative Classification • Leverage information from similar users: user-class matrix √ interested in X not interested in Also can be a value indicate degree of interests
Extending Collaborative Filtering (CF) Model to Ranking (Liu and Yang, SIGIR 008) • Previous method for CF: • Memory based approach: Finding users having similar interests to help predicting missing values • Model based approach: estimating probability based on new user’s known values • We propose a collaborative ranking model to improve model based approach • Using preference or ranking instead of values • better at estimating the preference for users
Item List Rating Prediction Ranking 1. Item y2 2. Item y3 Sort Predicted Ratings Nathan Liu and Qiang Yang. EigenRank: Collaborative Filtering via Rank Aggregation. In ACM SIGIR Conference (ACM SIGIR 08), Singapore, 2008 • Collaborative Ranking Framework Rating Database Active User Ratings
Collaborative Ranking for Intention Mining Input Output |Preference={(URL1<URL2)}| |Intention category| Preference Matrix Interest Score Matrix P(U|C) |Category| |user, or user group| Our objective is to uncover the interest probability P(U|C) consistent with the given observed preference for each query |User|
Solution: Automatically Generate LabeledData (to assist human labelers) C1 • Clickthrough • Connects queries and urls • Contains users’ personal interpretation for query User A Query url a || User B Query url b C2 We need the category information for urls …
How to enlarge training set? A HUGE number of clickthrough logs without labels A few human labeled data √ …. -…. √ …. √ …. -…. √ …. 1…. 2…. 3…. √ …. -…. √ …. 1…. 2…. 3…. √ …. -…. √ …. 1…. 2…. 3…. √ …. -…. √ …. √ …. -…. √ …. √ …. -…. √ …. - …. -…. √ …. √ …. -…. √ …. √ …. -…. √ …. - …. -…. √ …. -…. √ …. √ …. √ …. -…. √ …. √ …. -…. √ …. - …. √ …. √ …. √ …. -…. √ …. Online Knowledge Bases, such as ODP, Wikipedia
Online Knowledge Base such as WiKi Meaningful Ontology Plentiful Documents Knowledge Base Knowledge Base Links
“Label” Retrieval from Online KB Labels on result pages: Shopping: Commercial Sports: non-Commercial Video Games: Commercial Research:non-Commercial Taking Online Commercial Intention as an example Wikipedia Concept Graph Use labeled result pages as “Seeds” to retrieve the most relevant documents as training data
Obtain “Pseudo-Relevance” Data A few human labeled data A HUGE number of clickthrough logs We can use the HUGE “label” clickthrough log for evaluation √ …. -…. √ …. √ …. -…. √ …. 1…. 2…. 3…. √ …. -…. √ …. 1…. 2…. 3…. √ …. -…. √ …. 1…. 2…. 3…. √ …. -…. √ …. √ …. -…. √ …. √ …. -…. √ …. - …. -…. √ …. √ …. -…. √ …. √ …. -…. √ …. - …. -…. √ …. -…. √ …. √ …. √ …. -…. √ …. √ …. -…. √ …. - …. √ …. √ …. √ …. -…. √ …. We apply the classifier to “label” the HUGE clickthrough log We learn a classifier using the retrieved “labeled” documents
Preliminary results on F(URL)C • We evaluated the performance of the classifier trained with the relevant documents retrieved from Wikipedia • AOL query data set, 10,000 held out for test
Outline • Introduction • Profile based PQC • Context based PQC: Hao Hu, Huanhuan Cao, et al. @ SIGIR 2009, ACML 2009. • Conclusion
Context based PQC for Online Commercial Intention Allan Iverson shoes T-short Commercial! Offer ads! Michael Jordan The commercial intention of the same query can be identified given its context information
Context based PQC forOnlineCommercial Intention [Cao etc. SIGIR’09] Graphical Model Machine Learning UCB Non-Commercial! Redirect to scholar Search! Michael Jordan The commercial intention of the same query can be identified given its context information
Two questions: • How do we model query context? • How do we detect whether two queries are semantically similar? Graphical Models Feature Generation/Enrichment
Conditional Random Field Motivation: model the query logs as a conditional random field. Therefore, the relationships between consecutive and even skip queries can be modeled. Question: How do we decide whether two “skip queries” (non-consecutive queries) are related and should be linked?
Semantic Relationship between queries • Given Query A and Query B, how do we determine the degrees of relevancy of these two queries in a semantic level? • Send queries to search engines • Obtain search results • Determine distance between search results
Context based PQC for Online Commercial Intention • The commercial intention of the same query can be identified given its context information Allan Iverson shoes T-short Commercial! Offer ads! Michael Jordan
Context based PQC for Online Commercial Intention • The commercial intention of the same query can be identified given its context information Graphical Model Machine Learning UCB Non-Commercial! Redirect to scholar Search! Michael Jordan
Evaluation • Using context information • Vs • Not using context information
Preliminary Experimental Results of PQC for Online Commercial Intention • Dataset • AOL Query Log data • Around ~20M Web Queries • Around 650K Web users • Data is sorted by anonymous UserID and sequentially arranged. • Each item of clickthrough log data contains • {AnonID, Query, QueryTime, ItemRank, ClickURL}
Preliminary Results In our preliminary experimental studies, we annotated four users with the OCI (commercial / non-commercial) status in their clickthrough logs. More larger-scale experimental studies to be followed. Evaluation Metric: Standard F1-measure Baseline classifier: the classifier in Dai’s WWW 2006 work (http://adlab.msn.com/OCI/OCI.aspx)
Preliminary Results The parameter we tune is the threshold we use to determine whether we add the “skip edges” in the CRF model or not.
Ongoing work: Personalized Query Classification • Efficiency • More ground truth data for evaluation
PQC and Personalized Search • Similar input: • Query Log, Clickthrough Data, IP Address, etc. • Different output: • Personalized Search • ranked results • PQC • Discrete intention categories, • Application: advertisements etc.
Conclusions: PQC • Have user profile information? • Profile = <User, Query, URLs> • Output=Class • Method = Collaborative Ranking • Have query stream information? • Context = <User, Query-Stream, URLs> • Output=Class • Method = CRF-based method