Questioning Yahoo! Answers

Transcription

1 Questioning Yahoo! Answers Zoltán Gyöngyi

2 Outline Yahoo! Answers model Statistics Basics Diversity Authority Problems Interaction model Others Question Answering on the Web April 22,

3 Yahoo! Answers Model ask. Open answer. Undecided Resolved hand-picked voted Question Answering on the Web April 22,

4 Yahoo! Answers Model Browse Shallow hierarchy of categories Search Advanced search Keyword match in Qs, best As Category Filter by language/location Question status Date submitted No sorting criteria Health discover. Alternative Medicine Dental Diet & Fitness Women s Health Diseases and Conditions General Health Care Mental Health Men s Health Other Question Answering on the Web April 22,

5 Yahoo! Answers Model Post-resolution opinions Thumbs-up/ down votes Comments Interesting Save to User points/ levels Question Answering on the Web April 22,

6 Motivation: Search Question Answering on the Web April 22,

7 Motivation: Search Enable web-style search Improve ranking Relevance Query dependent Text-based Importance Query independent (global) Question Answering on the Web April 22,

8 Motivation: Search Importance Formulation of questions, answers Text analysis Popularity/community impact Many answers Many votes Involvement of influential users» Knowledgeable answerers (many best answers)» Good askers» Active users» Leading users Question Answering on the Web April 22,

9 Data Set 10 months: from August 2005 to May ,690,459 questions 895,137 voted 795,322 hand-picked 10,995,265 answers 2,971,000 votes 969,652 users 700,634 askers 545,104 answerers Question Answering on the Web April 22,

10 Statistics Basics Diversity Authority Question Answering on the Web April 22,

11 Qs & As per Period Months 08 & & & & & 05 Questions 194 1, , , ,257 Answers (Avg. per Q) 365 (1.88) 2,100 (2.04) 864,899 (3.72) 2,953,255 (5.47) 7,174,483 (7.82) Question Answering on the Web April 22,

12 Distributions Number of users Number of users Questions per user Power laws (above) Qs, As / user and not Answers per Q Limited exposure Number of questions Answers per user Answers per question Question Answering on the Web April 22,

13 Votes per Question Number of questions Votes per question Self votes: 782,583 (26.34%) 536,877 (60% v / 31.7% t) questions influenced 395,965 (44% v / 23.4% t) questions decided by a single vote, which was a self vote Question Answering on the Web April 22,

14 Categories Tree of 728 nodes 24 top-level categories (TLCs) 218 subcategories 486 subsubcategories under 10 TLCs Mostly geographical Average TLC per asker: out of 7 asks questions in a single TLC Average TLC per answerer: 3.5 Question Answering on the Web April 22,

15 Qs, As per Category Questions per Category A/Q ratio Ar Bu Ca Co Cn Di Ed En Fo Ga He Ho Lo Lv Ne Ot Pe Po Pr Sc So Sp Tr Y! Categories Question Answering on the Web April 22,

16 # of Questions vs. # of TLCs Categories per Asker Questions per Asker Question Answering on the Web April 22,

17 # of Answers vs. # of TLCs Categories per Answerer Answers per Answerer Question Answering on the Web April 22,

18 Assessing Authority Nodes Users (askers and answerers) Questions Answers (best and not best) Links 3 3 Question Answering on the Web April 22,

19 Assessing Authority Disregard Text Votes Points Thumbs-up/down Comments Question Answering on the Web April 22,

20 Assessing Authority 1 Which links to trust? Question Answering on the Web April 22,

21 Assessing Authority Which links to trust? Best answers Question Answering on the Web April 22,

22 Assessing Authority Which links to trust? Best answers Question Answering on the Web April 22,

23 Assessing Authority Randomized hubs & authorities Authorities = users providing many best answers to important questions Hubs = users asking important questions bestanswered by authorities auth = ε 1 + (1 ε) A T row hub hub = ε 1 + (1 ε) A col auth random jump (~ 0.1) adjacency matrix Question Answering on the Web April 22,

24 All Answers vs. Authority Question Answering on the Web April 22,

25 Best Answers vs. Authority Question Answering on the Web April 22,

26 Best / All Answers vs. Authority Question Answering on the Web April 22,

27 Points vs. Authority Question Answering on the Web April 22,

28 Points vs. Authority Question Answering on the Web April 22,

29 Points vs. Authority Question Answering on the Web April 22,

30 Problem: Interaction Model 3 types of interaction 1. Focused question / expert answer Can CDs be shipped as Media Mail? Original intention 2. Opinions, discussions Do you like country music? What do you think about? No support for (sub)threads Question Answering on the Web April 22,

31 Problem: Interaction Model 3 types of interaction (cont d) 3. (In between) Where can I get the best French bread in SF? 4. Chat Anyone online now? No support for real-time interaction Questions How to facilitate each type? How to avoid interference? Question Answering on the Web April 22,

32 More Problems Ranking Finding similar users Identifying potential expert answerers Information push/pull Suggesting categories, tags Question Answering on the Web April 22,

33 Summary Yahoo! Answers 10 months (08/05-05/06) Rapid adoption, increase in average A / Q 70% of users ask, 55% of answer, 28% do both User interest typically spans 2-4 TLCs Some correlation between authority, points Problems Interaction model Ranking, recommendations Question Answering on the Web April 22,