Joint Models of Disagreement and Stance in Online Debate Dhanya Sridhar, James Foulds, Bert Huang, Lise Getoor, Marilyn Walker University of California, Santa Cruz Virginia Institute of Technology
Social media sites for debating issues Valuable resources for: –Argumentation –Dialogue –Sentiment –Opinion mining 2 Online Debate Forums
CreateDebate.org 3
4 Debate topic
CreateDebate.org 5 Debate topic Posts
CreateDebate.org 6 Debate topic Posts Replies
CreateDebate.org 7 Debate topic Posts Replies Reply polarity
4Forums.com 8
9 Quotation
Graph of posts: tree structure Online Debate Forums 10 Graph of users: loopy structure = reply link
Graph of posts: tree structure Online Debate Forums 11 Graph of users: loopy structure
Zoom in on an Example 12
Zoom in on an Example 13
I believe Obama is likely the worst! He’s been infinitely more effective than Bush! Zoom in on an Example 14
I believe Obama is likely the worst! He’s been infinitely more effective than Bush! Anti Obama Pro Obama Task: Stance Classification 15 Useful for advocacy and get-out-the-vote campaigns
I believe Obama is likely the worst! He’s been infinitely more effective than Bush! Anti Obama Pro Obama Task: Stance Classification 16 Study argumentation and dialogue Posts express stance
I believe Obama is likely the worst! He’s been infinitely more effective than Bush! Anti Obama Pro Obama Task: Disagreement Classification 17 Study argumentation and dialogue Disagree on stance
I believe Obama is likely the worst! He’s been infinitely more effective than Bush! Anti Obama Pro Obama Task: Disagreement Classification 18 Study argumentation and dialogue Disagree on stance Posts express disagreement
Stance Classification Targets 19 Stance Author-level Post-level Disagreement Author-level Post-level Textual
Stance Disagrees Classification Targets 20 Stance Author-level Post-level Disagreement Author-level Post-level Textual
Stance Disagrees Classification Targets 21 Stance Author-level Post-level Disagreement Author-level Post-level Textual
Related Work Walker et. al (2012), Decision Support Sciences State-of-the-art local stance classifier using linguistic features Walker et. al (2012), NAACL Collective stance classification using MaxCut over rebuttal links Hasan and Ng. (2013), EMNLP Collective stance sequence labeling with CRF; benefits of user stance consistency constraint Abbott et. al (2012), ACL Local disagreement classifier using linguistic features Burfoot et. al (2011), ACL Joint classification of stance and reply polarity in Congressional debates 22
Related Work Walker et. al (2012), Decision Support Sciences State-of-the-art local stance classifier using linguistic features Walker et. al (2012), NAACL Collective stance classification using MaxCut over rebuttal links Hasan and Ng. (2013), EMNLP Collective stance sequence labeling with CRF; benefits of user stance consistency constraint Abbott et. al (2012), ACL Local disagreement classifier using linguistic features Burfoot et. al (2011), ACL Joint classification of stance and reply polarity in Congressional debates 23
Related Work Walker et. al (2012), Decision Support Sciences State-of-the-art local stance classifier using linguistic features Walker et. al (2012), NAACL Collective stance classification using MaxCut over rebuttal links Hasan and Ng. (2013), EMNLP Collective stance sequence labeling with CRF; benefits of user stance consistency constraint Abbott et. al (2012), ACL Local disagreement classifier using linguistic features Burfoot et. al (2011), ACL Joint classification of stance and reply polarity in Congressional debates 24
Related Work Walker et. al (2012), Decision Support Sciences State-of-the-art local stance classifier using linguistic features Walker et. al (2012), NAACL Collective stance classification using MaxCut over rebuttal links Hasan and Ng. (2013), EMNLP Collective stance sequence labeling with CRF; benefits of user stance consistency constraint Abbott et. al (2012), ACL Local disagreement classifier using linguistic features Burfoot et. al (2011), ACL Joint classification of stance and reply polarity in Congressional debates 25
Related Work Walker et. al (2012), Decision Support Sciences State-of-the-art local stance classifier using linguistic features Walker et. al (2012), NAACL Collective stance classification using MaxCut over rebuttal links Hasan and Ng. (2013), EMNLP Collective stance sequence labeling with CRF; benefits of user stance consistency constraint Abbott et. al (2012), ACL Local disagreement classifier using linguistic features Burfoot et. al (2011), ACL Joint classification of stance and reply polarity in Congressional debates 26
Stance Classification: “Teach the Controversy” Previous work employs many modeling strategies How best to model stance in online debate? Answers may be different to Congressional debates –Links have different semantics –Posts much shorter than speeches. Many posts per author –Dialogue is informal 27
Stance Classification: “Teach the Controversy” Previous work employs many modeling strategies How best to model stance in online debate? Answers may be different to Congressional debates –Links have different semantics –Posts much shorter than speeches. Many posts per author –Dialogue is informal 28
Stance Modeling at author-level or post-level? 29 [Hasan and Ng 2013] [Other Related Work] Modeling Question 1)
Stance Modeling at author-level or post-level? 30 [Hasan and Ng 2013] [Other Related Work] Modeling Question 1)
Stance Modeling Question 2) 31 [Walker et al. 2012, Hasan and Ng 2013] Collective classification vs. local classification?
Stance Modeling Question 2) 32 [Walker et al. 2012, Hasan and Ng 2013 ] [Walker et al. 2012] Collective classification vs. local classification?
Stance Disagrees 33 Jointly model disagreement together with stance? [Abbott et. al Linguistic Features], [Burfoot et. al 2011 for Congressional Debates] Modeling Question 3)
Stance Disagrees 34 Jointly model disagreement together with stance? [Abbott et. al Linguistic Features], [Burfoot et. al 2011 for Congressional Debates] Modeling Question 3) Stance Disagrees Stance
Our Contributions A unified framework to explore multiple models Fast, highly scalable inference –Large post-level graphs –Loopy author-level graphs Systematic study of modeling options 35
Our Contributions A unified framework to explore multiple models Fast, highly scalable inference –Large post-level graphs –Loopy author-level graphs Systematic study of modeling options 36
Our Contributions A unified framework to explore multiple models Fast, highly scalable inference –Large post-level graphs –Loopy author-level graphs Systematic study of modeling options –Modeling recommendations 37
Author Post Local Collective Joint Author Local Author Coll. Author Joint Post Local Post Joint Post Coll. Modeling Granularity Statistical Models All Combinations of Models 38
Probabilistic Soft Logic (PSL) Templating language for highly scalable graphical model called Hinge-loss Markov Random Fields 39 Bach et. al (2015), ArXiV Open source software: 5.0: Disagrees(A1, A2) ^ Pro(A1) ~Pro(A2) Rule Weight
Probabilistic Soft Logic (PSL) Templating language for highly scalable graphical model called Hinge-loss Markov Random Fields : Disagrees(A1, A2) ^ Pro(A1) ~Pro(A2) Rule Weight Predicates are continuous Random Variables!
Probabilistic Soft Logic (PSL) Templating language for highly scalable graphical model called Hinge-loss Markov Random Fields : Disagrees(A1, A2) ^ Pro(A1) ~Pro(A2) Rule Weight Predicates are continuous Random Variables! Relaxations of Logical Operators
Probabilistic Soft Logic (PSL) Rules instantiated with variables from real network : Disagrees(A1, A2) ^ Pro(A1) ~Pro(A2) Stance Disagrees
Probabilistic Soft Logic (PSL) Rules instantiated with variables from real network : Disagrees(, ) ^ Pro( ) ~Pro( ) … Continuous Random Variables!
Hinge-loss MRFs Over Continuous Variables Bach et al. NIPS 12, Bach et al. UAI Bach et al. (2015), ArXiV Conditional random field over continuous RVs in [0,1]
Hinge-loss MRFs Over Continuous Variables Bach et al. NIPS 12, Bach et al. UAI Conditional random field over continuous RVs in [0,1] Feature function for each instantiated rule 5.0: Disagrees(, ) ^ Pro( ) ~Pro( )
Hinge-loss MRFs Over Continuous Variables Bach et al. NIPS 12, Bach et al. UAI Conditional random field over continuous RVs in [0,1] Feature functions are hinge-loss functions
Hinge-loss MRFs Over Continuous Variables Bach et al. NIPS 12, Bach et al. UAI Encodes distance to satisfaction of each instantiated rule Linear function
Fast Inference in Hinge-loss MRFs Bach et al. NIPS 12, Bach et al. UAI Convex, continuous inference objective… Convex optimization! Solved using efficient, parallelizable algorithm: Alternating Direction Method of Multipliers (ADMM)
Unigrams, Bigrams, Lengths, Initial n-grams, Repeated Punctuation Obama Bush believe Constructing Local Predictors 49 Bag-of-words
Unigrams, Bigrams, Lengths, Initial n-grams, Repeated Punctuation Logistic Regression Obama Bush believe Constructing Local Predictors 50 Pro Not Pro Bag-of-words Training Labels
Unigrams, Bigrams, Lengths, Initial n-grams, Repeated Punctuation Logistic Regression Observed Prediction Probabilities Obama Bush believe Constructing Local Predictors 51 Pro Not Pro Bag-of-words Training Labels LocalPro: 0.8 LocalPro: 0.1
PSL Rules Shared by All Models 52 Stance LocalPro: 0.8 LocalPro: 0.1
PSL Rules for Simple Collective Models 53 Stance Disagrees: 1.0 LocalPro: 0.8 LocalPro: 0.1
Joint Disagreement Models 54 Stance Disagrees LocalPro: 0.8 LocalPro: 0.1 LocalDis: 0.5
Joint Disagreement Models 55 Stance Disagrees LocalPro: 0.8 LocalPro: 0.1 LocalDis: 0.5
Details4Forums.comCreateDebate.org TopicsAbortion, Gay Marriage, Evolution, Gun Control Abortion, Gay Rights, Obama, Marijuana Avg. Users/Topic Avg. Posts/User 194 Evaluation - Datasets 56
Evaluation Settings Prediction Tasks: Author Stance, Post Stance 57
Evaluation Settings Prediction Tasks: Author Stance, Post Stance 58 Ground Truth for CreateDebate.org: Stance Majority
Evaluation Settings Prediction Tasks: Author Stance, Post Stance 59 Ground Truth for CreateDebate.org: Stance Majority Ground Truth for 4Forums: Stance
60 Post Local Post Coll. Post Joint Author Local Author Coll. Author Joint Accuracy Author Stance Prediction – CreateDebate.org
61 Post Local Post Coll. Post Joint Author Local Author Coll. Author Joint Accuracy Author Stance Prediction – CreateDebate.org Post < Author
62 Post Local Post Coll. Post Joint Author Local Author Coll. Author Joint Accuracy Author Stance Prediction – CreateDebate.org Post < Author Author-Joint Model is best
63 Accuracy Post Local Post Coll. Post Joint Author Local Author Coll. Author Joint Post Stance Prediction – CreateDebate.org Post < Author (still!) Author-Joint Model still best!
64 Post Local Post Coll. Post Joint Author Local Author Coll. Author Joint Accuracy Author Stance Prediction – CreateDebate.org Local < Collective < Joint
65 Post Local Post Coll. Post Joint Author Local Author Coll. Author Joint Accuracy Naïve collective harmful at author level! Author Stance Prediction – 4Forums.com
66 Post Local Post Coll. Post Joint Author Local Author Coll. Author Joint Accuracy Author Stance Prediction – 4Forums.com Naïve collective harmful at author level!
Details4Forums.comCreateDebate.org % Opposite Stance Posts % Opposite Stance Authors Explanation for Naïve Collective’s Performance 67
Details4Forums.comCreateDebate.org % Opposite Stance Posts % Opposite Stance Authors Explanation for Naïve Collective’s Performance 68 Naïve collective assumption mostly true for posts
Details4Forums.comCreateDebate.org % Opposite Stance Posts % Opposite Stance Authors Explanation for Naïve Collective’s Performance 69 Naïve collective assumption mostly true for posts Assumption doesn’t hold at author level!
70 I agree with everything except the last part. Safe gun storage is very important… I agree with everything except the last part. Safe gun storage is very important… I can agree with this. And in case it seemed otherwise, I know full well how to store guns safely… My point was that I don’t like the idea of such a law… I can agree with this. And in case it seemed otherwise, I know full well how to store guns safely… My point was that I don’t like the idea of such a law… Benefit of Disagreement Prediction Agree Anti Gun Control
71 I agree with everything except the last part. Safe gun storage is very important… I agree with everything except the last part. Safe gun storage is very important… I can agree with this. And in case it seemed otherwise, I know full well how to store guns safely… My point was that I don’t like the idea of such a law… I can agree with this. And in case it seemed otherwise, I know full well how to store guns safely… My point was that I don’t like the idea of such a law… Benefit of Disagreement Prediction Agree Anti Gun Control
Summary Unified modeling framework for efficiently, systematically exploring all modeling choices Author-level joint disagreement and stance model best, even for post-level prediction Disagreement model can be vital when modeling at author level 72
Summary Unified modeling framework for efficiently, systematically exploring all modeling choices Author-level joint disagreement and stance model best, even for post-level prediction Disagreement model can be vital when modeling at author level 73
Summary Unified modeling framework for efficiently, systematically exploring all modeling choices Author-level joint disagreement and stance model best, even for post-level prediction Disagreement model can be vital when modeling at author level 74
Summary Unified modeling framework for efficiently, systematically exploring all modeling choices Author-level joint disagreement and stance model best, even for post-level prediction Disagreement model can be vital when modeling at author level 75 Thank you for your attention!