Integration of Heterogeneous Databases without Common Domains Using Queries Based on Textual Similarity: William W. Cohen Machine Learning Dept. and Language Technologies Inst. School of Computer Science Carnegie Mellon University Embodied Cognition and Knowledge

What was that paper, and who is this guy talking? Representation languages: DBs, KR Human languages: NLP, IR Machine Learning WHIRL Word-Based Heterogeneous Information Representation Language

History 1982/1984: Ehud Shapiro’s thesis: –MIS: Learning logic programs as debugging an empty Prolog program –Thesis contained 17 figures and a 25-page appendix that were a full implementation of MIS in Prolog –Incredibly elegant work “ Computer science has a great advantage over other experimental sciences: the world we investigate is, to a large extent, our own creation, and we are the ones to determine if it is simple or messy.”

History Grad school in AI at Rutgers MTS at AT&T Bell Labs in group doing KR, DB, learning, information retrieval, … My work: learning logical (description-logic-like, Prolog-like, rule-based) representations that model large noisy real-world datasets

History AT&T Bells Labs becomes AT&T Labs Research The web takes off –as predicted by Vinge and Gibson IR folks start looking at retrieval and question-answering with the Web Alon Halevy starts the Information Manifold project to integrate data on the web –VLDB year Best Paper Award for 1996 paper on IM I started thinking about the same problem in a different way…

History: WHIRL motivation 1 As the world of computer science gets richer and more complex, computer science can no longer limit itself to studying “our own creation”. Tension exists between –Elegant theories of representation –The not-so-elegant real world that is being represented CA

History: WHIRL motivation 1 The beauty of the real world is its complexity…

History: integration by mediation Mediator translates between the knowledge in multiple separate KBs Each KB is a separate “symbol system” –No formal connection between them except via the mediator

WHIRL idea: exploit linguistic properties of the HTML “veneer” of web-accessible DBs TFIDF similarity WHIRL Motivation 2: Web KBs are embodied

Link items as needed by Q Query Q SELECT R.a,S.a,S.b,T.b FROM R,S,T WHERE R.a=S.a and S.b=T.b R.aS.aS.bT.b Anhai Doan Dan Weld Strongest links: those agreeable to most users WilliamWillCohenCohn SteveStevenMintonMitton Weaker links: those agreeable to some users WilliamDavidCohenCohn even weaker links…

Link items as needed by Q WHIRL approach: Query Q SELECT R.a,S.a,S.b,T.b FROM R,S,T WHERE R.a~S.a and S.b~T.b (~ TFIDF-similar) R.aS.aS.bT.b Anhai Doan Dan Weld Incrementally produce a ranked list of possible links, with “best matches” first. User (or downstream process) decides how much of the list to generate and examine. WilliamWillCohenCohn SteveStevenMintonMitton WilliamDavidCohenCohn

WHIRL queries Assume two relations: review(movieTitle,reviewText): archive of reviews listing(theatre, movieTitle, showTimes, …): now showing The Hitchhiker’s Guide to the Galaxy, 2005 This is a faithful re-creation of the original radio series – not surprisingly, as Adams wrote the screenplay …. Men in Black, 1997 Will Smith does an excellent job in this … Space Balls, 1987 Only a die-hard Mel Brooks fan could claim to enjoy … …… Star Wars Episode III The Senator Theater 1:00, 4:15, & 7:30pm. Cinderella Man The Rotunda Cinema 1:00, 4:30, & 7:30pm. ………

WHIRL queries “Find reviews of sci-fi comedies [movie domain] FROM review SELECT * WHERE r.text~’sci fi comedy’ (like standard ranked retrieval of “sci-fi comedy”) “ “Where is [that sci-fi comedy] playing?” FROM review as r, LISTING as s, SELECT * WHERE r.title~s.title and r.text~’sci fi comedy’ (best answers: titles are similar to each other – e.g., “Hitchhiker’s Guide to the Galaxy” and “The Hitchhiker’s Guide to the Galaxy, 2005” and the review text is similar to “sci-fi comedy”)

WHIRL queries Similarity is based on TFIDF  rare words are most important. Search for high-ranking answers uses inverted indices…. The Hitchhiker ’s Guide to the Galaxy, 2005 Men in Black, 1997 Space Balls, 1987 … Star Wars Episode III Hitchhiker ’s Guide to the Galaxy Cinderella Man … Years are common in the review archive, so have low weight hitchhikermovie00137 themovie001,movie003,movie007,movie008, movie013,movie018,movie023,movie0031, ….. - It is easy to find the (few) items that match on “ important ” terms - Search for strong matches can prune “unimportant terms”

After WHIRL Efficient text joins On-the-fly, best-effort, imprecise integration Interactions between information extraction quality and results of queries on extracted data Keyword search on databases Use of statistics on text corpora to build intelligent “embodied” systems Turney: solving SAT analogies with PMI over word pairs Mitchell & Just: predicting FMI brain images resulting from reading a common noun (“hammer”) from co-occurrence information between nouns and verbs

Recent work: non-textual similarity “William W. Cohen, CMU” “Dr. W. W. Cohen” cohen williamw dr cmu “George W. Bush” “George H. W. Bush” “Christos Faloutsos, CMU”

Recent Work Personalized PageRank aka Random Walk with Restart: –Similarity measure for nodes in a graph, analogous to TFIDF for text in a WHIRL database –natural extension to PageRank –amenable to learning parameters of the walk (gradient search, w/ various optimization metrics): Toutanova, Manning & NG, ICML2004; Nie et al, WWW2005; Xi et al, SIGIR 2005 –various speedup techniques exist –queries: Given type t* and node x, find y:T(y)=t* and y~x

proposal CMU CALO graph William 6/18/07 6/17/07 Sent To Term In Subject Learning to Search [SIGIR 2006, CEAS 2006, WebKDD/SNA 2007] Einat Minkov, CMU; Andrew Ng, Stanford

Tasks that are like similarity queries Person name disambiguation Threading Alias finding [ term “andy” file msgId ] “person” [ file msgId ] “file”  What are the adjacent messages in this thread?  A proxy for finding “more messages like this one” What are the -addresses of Jason ?... [ term Jason ] “ -address” Meeting attendees finder Which -addresses (persons) should I notify about this meeting? [ meeting mtgId ] “ -address”

Results on one task Mgmt. game PERSON NAME DISAMBIGUATION

Results on several tasks (MAP) Name disambiguation Threading Alias finding * * * * * * * * * * * *

Set Expansion using the Web Fetcher: download web pages from the Web Extractor: learn wrappers from web pages Ranker: rank entities extracted by wrappers 1.Canon 2.Nikon 3.Olympus 4.Pentax 5.Sony 6.Kodak 7.Minolta 8.Panasonic 9.Casio 10.Leica 11.Fuji 12.Samsung 13.… Richard Wang, CMU

The Extractor Learn wrappers from web documents and seeds on the fly –Utilize semi-structured documents –Wrappers defined at character level No tokenization required; thus language independent However, very specific; thus page-dependent –Wrappers derived from document d is applied to d only

Ranking Extractions A graph consists of a fixed set of… –Node Types: {seeds, document, wrapper, mention} –Labeled Directed Edges: {find, derive, extract} Each edge asserts that a binary relation r holds Each edge has an inverse relation r -1 (graph is cyclic) “ford”, “nissan”, “toyota” curryauto.com Wrapper #3 Wrapper #2 Wrapper #1 Wrapper #4 “honda” 26.1% “acura” 34.6% “chevrolet” 22.5% “bmw pittsburgh” 8.4% “volvo chicago” 8.4% find derive extract northpointcars.com Minkov et al. Contextual Search and Name Disambiguation in using Graphs. SIGIR 2006

Evaluation Method Mean Average Precision –Commonly used for evaluating ranked lists in IR –Contains recall and precision-oriented aspects –Sensitive to the entire ranking –Mean of average precisions for each ranked list Evaluation: Average over 36 datasets in three languages (Chinese, Japanese, English) 1.Average over several 2- or 3-seed queries for each dataset. 2.MAP performance: high 80s - mid 90s 3.Google Sets: MAP in 40s, only English where L = ranked list of extracted mentions, r = rank Prec ( r ) = precision at rank r (a) Extracted mention at r matches any true mention (b) There exist no other extracted mention at rank less than r that is of the same entity as the one at r # True Entities = total number of true entities in this dataset

Evaluation Datasets

Top three mentions are the seeds Try it out at

Relational Set Expansion Seeds

Future? Representation languages: DBs, KR Human languages: NLP, IR Machine Learning