COMPUTATIONAL TIE STRENGTH:THEORY AND APPLICATIONSEric Gilbert’s Prelim

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casey

leslielucas

kevin

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The strength of a tie is a (probably linear) combination of the amount of TIME, the emotional INTENSITY, the INTIMACY (mutual confiding), and the reciprocal SERVICES which characterize the tie. — Granovetter

TIE STRENGTHconcept & impact

STRONG TIES are the people you really trust.

WEAK TIES, conversely, are merely acquaintances.

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7,000+ papers cite TSOWT

firms with right mix of ties get better deals

strong ties can affect mental health

TIE STRENGTHconcept & impact

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USING ITin design & analysis

2 make better friend introductions.

1 build more informed privacy controls.

3 rethink social streams.

4 analyze large-scale, networked phenomena.

MODEL TIE STRENGTH TO…

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This thesis will show how to RECONSTRUCT it from digital traces, and how to apply it as a DESIGN and ANALYTIC tool.

Tie strength is a blind spot in social media.

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HEURISTICSa sample of substitutes

communication reciprocity [19] Friedkin 1980

one mutual friend [56] Shi, Adamic & Strauss 2007

communication recency [41] Lin, Dayton & Greenwald 1978

interaction frequency [22] Gilbert, Karahalios & Sandvig 2008

[17] Fischer, et al. 2006

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HEURISTICSthe difference

CHI 2009 MODEL 88% Adj. R2 = 0.53

MSGS → FRIEND 62% Adj. R2 = 0.09

BASELINE 52%

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COMPUTATIONAL TIE STRENGTHPART ONE

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DIGITAL TRACESour interactions leave marks

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THE MAPPING PROBLEM

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RESEARCH QUESTIONS

The literature suggests seven dimensions of tie strength: INTENSITY, INTIMACY, DURATION, RECIPROCAL SERVICES, STRUCTURAL, EMOTIONAL SUPPORT and SOCIAL DISTANCE.

As manifested in social media, can these dimensions predict tie strength? In what combination?

R1.

What are the limitations of a tie strength model based SOLELY on social media?

R2.

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THE DATAoverview

2,184 assessed friendships

from 35 university students & staff

described by 70+ numeric indicators

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ASSESSING TIE STRENGTHparticipant interface

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STATISTICAL METHODS

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87.6% accuracyχ2(1, N = 4368) = 700.9

p < 0.001

THE MODELperformance

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0

1

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+μ

μ

prediction

participant

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DELIVERABLESpart one

multicollinearity & structure

tough dimensions … new techniques

the predictors vs. accuracy tradeoff

five flavors of tie strength

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DESIGNING AROUND TIE STRENGTHPART TWO

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RESEARCH QUESTIONS

How GENERAL is the tie strength model? Does it work in a new medium, like Twitter?

R1.

Can automatically-inferred tie strength usefully INFORM DESIGN

in the real world? Can it help the collapsed context problem?R2.

Can feedback from users IMPROVE the model? If so, how does it change?

R3.

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collision of social circles which normally remain separateTHE COLLAPSED CONTEXT PROBLEM

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We Meddle demovideo at wemeddle.com

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RT @Francesca_Elle teens don't tweet is a trending topic WTF ! Teens DO Tweet ... 2m ago from R E D L O G

The Logo Evolution of Coca-Cola and Pepsi. 5m ago from D A R I N G F I R E B A L L

Motorola Unveils Cliq: http://df.ws/dqx 14m ago from D A R I N G F I R E B A L L

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WE MEDDLE arranges things just for you. You can emphasize either your inner circle or your outer circle. If we put somebody in the wrong one, you can fix it: try hovering over a profile icon. Also, we hope you enjoy our filters above. We're in private alpha.

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twitter screenname, then press enter

New Typekit JS is live - just 1/10 the size! (about 2k for sites w/o badge. All sites soon). Republish your kits to upgrade. 57m ago from J A S O N S A N TA M A R I A

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[17] Fischer, et al. 2006

[62] Whittaker, et al. 2004.

RELATED SYSTEMSsocially-rendered interfaces

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METHODShow general is the model?can feedback improve it?

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METHODScan tie strength usefully inform design?

QUALITATIVE EVALUATION with We Meddle’s users

10 – 20 semi-structured interviews centered on usage and utility

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TIE STRENGTH & DIFFUSIONPART THREE

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Dichotomous distinctions [edge exists or not] can sometimes be misleading … a weighted graph representation will frequently be more appropriate. More studies that assess the effectiveness of such approximations — and provide concrete, empirically validated guidelines for practice within particular problem domains — would be a welcome addition to the literature.— 2009 Science article “Revisiting the Foundations of Network Analysis”

TIE STRENGTHits potential in diffusion studies

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DIFFUSIONevery link is equal

Fowler & Christakis. 2008. Dynamic Spread of Happiness … BMJ.

Ivkovic & Weisbenner. 2007. Information Diffusion Effects in Individual Investors' Common Stock Purchases … Rev. Fin.

Kossinets, Kleinberg & Watts. 2008. The Structure of Information Pathways in a Social Communication Network. KDD.

Onnela, et al. 2007. Structure and Tie Strengths in Mobile Communication Networks. PNAS.

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WEIGHTED DIFFUSIONfrom Onnela, et al.

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RESEARCH QUESTIONS

Does tie strength modulate the flow of information through a network?

R1.

Does tie strength interact with content as it flows through a network?

R2.

If tie strength regulates information flow through a network, how does this affect macroscopic properties of diffusion?

R3.

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METHODthe retweet

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METHODvalue-ladencontent

1 link per 700 tweets ⇒ 1000–1500 users

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COMPUTATIONAL TIE STRENGTH:THEORY AND APPLICATIONSEric Gilbert

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Days since last communication

Days since first communication

Intimacy × Structural

Wall words exchanged

Mean strength of mutual friends

Educational difference

Structural × Structural

Reciprocal Serv. × Reciprocal Serv.

Participant-initiated wall posts

Inbox thread depth

Participant’s number of friends

Inbox positive emotion words

Social Distance × Structural

Participant’s number of apps

Wall intimacy words

–0.762

0.755

0.4

0.257

–0.223

0.195

–0.19

0.146

–0.137

–0.136

0.135

0.13

–0.122

0.111

0.299

MOST PREDICTIVEby |beta|

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