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Carnegie Mellon University Influences of a Shocking News Event on Web Browsing D ANAI K OUTRA P AUL B ENNETT E RIC H ORVITZ TAIA ’14 (SIGIR), Gold Coast,

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Presentation on theme: "Carnegie Mellon University Influences of a Shocking News Event on Web Browsing D ANAI K OUTRA P AUL B ENNETT E RIC H ORVITZ TAIA ’14 (SIGIR), Gold Coast,"— Presentation transcript:

1 Carnegie Mellon University Influences of a Shocking News Event on Web Browsing D ANAI K OUTRA P AUL B ENNETT E RIC H ORVITZ TAIA ’14 (SIGIR), Gold Coast, Australia

2 In a nutshell - What? Focus on polarizing topics topics for which there exist ‘many’ different / contradictory opinions

3 Genetically Modified Food

4 Gun Control

5 In a nutshell - What? Focus on polarizing topics. - Why? Often the issued queries reveal our opinions, which are in turn reinforced by the search engines.

6 In a nutshell - What? Focus on polarizing topics. - Why? Often the issued queries reveal our opinions, which are in turn reinforced by the search engines. - Goal: Make all results accessible, and allow the user to skip them.

7 Steps along this path  Understand how people browse webpages on a polarizing topic

8 Steps along this path  Understand how people browse webpages on a polarizing topic  Time evolution + effect of events How does user browsing behavior change after an event? How do external events affect the polarity of a topic over time?

9 Data and time period to study

10 Sandy Hook Elementary Shooting Dec 14, 2012  Where: Sandy Hook Elementary, Newtown, Connecticut, USA  Who: Single perpetrator (20 yo male)  Historical significance: Most deadly shooting in US History at high-school or grade-school and second deadliest mass shooting in US History by a single perpetrator.  Casualties: 20 children (mostly 6 or 7 yo’s), 6 staff members, perpetrator’s mother, perpetrator  Primary Weapon: Legally acquired (by mother) semi-automatic Bushmaster XM15-E2S rifle with multiple 30-round magazines  At school: 154 shots with rifle, 2 shots with pistol  Primary Span: 5 minutes (all shootings except mother)  9:35 a.m. Shooter enters, 9:35:39 a.m. 911, 9:39:00 a.m. Police on scene, 9:40:03 a.m. shooter suicide  Motive: none determined  Other factors: multiple psychological conditions RQ: Does a shocking event of historical significance prompt both sides of a debate to explore the views of the other side? As evidenced by search and browsing behavior Over non-news articles (indicates intent to explore topic rather than simply follow news) On topic (any of guns, gun rights, and gun control)

11 Data Data source: web browser toolbar logs (search + browsing behavior) Topic: gun control Event: Sandy Hook shooting

12 Data Data source: web browser toolbar logs (search + browsing behavior) Topic: gun control Event: Sandy Hook shooting Longer time period to compensate for the increased activity after the event

13 Data extraction, cleaning

14 Data Extraction: Main Idea ◦Start from queries that are on-topic + ◦Expand them to get more relevant queries and URLs

15 Data Extraction: Identification of Relevant Queries Identify relevant queries and URLs: (a) find seed queries from the whole period ◦Queries containing one of the phrases: gun control, gun rights (b) get relevant queries ◦By doing 2-step random walk on the query-click graph

16 Data Extraction: Identification of Relevant Queries

17 Data Extraction: Identification of Relevant URLs Relevant query Relevant URL irrelevant query X Click trail 1 Click trail 2

18 Data Event: Sandy Hook shooting

19 Data Labeling

20 Labeling the webpages -Label all non-news on-topic sites visited by at least two users -2 assessors -Self-identified moderate gun rights -Self-identified moderate gun control -6 labels: extreme gun control, moderate gun control, highly balanced, purely factual, moderate gun rights, extreme gun rights -3 labels: gun control, balanced, gun rights …

21 Labeling the webpages -2 assessors -6 labels: extreme gun control, moderate gun control, highly balanced, purely factual, moderate gun rights, extreme gun rights -3 labels: gun control, balanced, gun rights …Inter-rater agreement:

22 Temporal Evolution

23 Daily visits for all users The event clearly had considerable influence on information seeking about gun control related topics.

24 Normalized daily visits for all users Gun Ban List Gun control petition Sandy Hook Bob Costas

25 Web Transitions

26 Goals 1.Which are the most common transitions? 2.Are there changes in transitions due to the news on the Newtown shootings? => obtain a micro-level view of information consumption patterns.

27 Setup for Analysis

28 Transition matrices for all users Immobility ratio IR = % same-state transitions IR = % transitions are same state

29 Transition matrices for all users Immobility ratio IR = % same-state transitions IR = % transitions are same state 50% transitions toward extreme gun rights only 25% transitions toward extreme gun control Moving up MU = % transitions from control to rights MU = Moving up MD = % transitions from rights to control MD =0.2518

30 Change in transition matrices for common users After the event: Immobility (IR)  Control -> Rights (MU)  Rights -> Control (MD)  Before S.H. After S.H. After S.H. Mobility Indices

31 Change in transition matrices for common users After the event: Immobility (IR)  Control -> Rights (MU)  Rights -> Control (MD)  Before S.H. After S.H. After S.H. Mobility Indices Overall, the system moves towards extreme stances and mainly exploration of gun rights.

32 Conclusions ◦Topically ◦People use the web to largely access agreeable information. ◦Half of the transitions are from gun control to gun rights pages. ◦After the shootings, the system moves into extreme stances, and mainly towards content taking an extreme gun rights stance. ◦Methodologically ◦Mobility indices/Matrix distances as change measure ◦All users vs users observed both before/after ◦Entropy as a diversity measure

33 Thank you! / /

34 Why is it a hard problem?  Users often ask biased queries  Common users before/after an external event are needed (common = active both before and after the event)  Data is sparse VS.

35 How to compare the two transition matrices? Before S.H. After S.H. After S.H. Matrix distances! P = Q =

36 How to compare the two transition matrices? L1-norm: L2-norm: D1: D3: Risk-adjusted difference indices

37 How to compare the two transition matrices? Hint: The distances from the perfectly immobile system increase. More different-state transitions after S.H.

38 How to compare the two transition matrices? Hint: The distances from the perfectly immobile system increase in absolute value. Negative signs: The majority of transitions are towards gun rights webpages.

39 Are balanced webpages bridges between opposing views? Most transitions between the two sides occur directly, without accessing balanced webpages. ?

40 Future work: Location based analysis less diverse more diverse Change in user diversity after S.H. (per state)


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