Literature Review

Carlos Figueiredo
Emotional Response and
Bridging ties on Social Networks
Research Question
intervene in the Surprise Response
Literature Review
in Information Sharing
Research Methods
Desired Contributions
Interpreting how Individual Attributes
and Social Graph Properties
Digital Media Research Methods
Porto, DiMe 24th May 2013
 Make a contribution to solve the problem of
the ‘Portfolio Effect’ on Recommender System
(e.g. content recommendation).
 Measure novelty in an information flow.
 Propose a methodology to measure and
predict the delivering of novelty.
Recommender Systems
“You bought, liked or
shared a bunch of
things like Y”
“People like you
bought, liked or
shared Y”
Trust-Based CF
“People who bought,
liked or shared X
also bought, liked or
shared Y”
e.g. Amazon
(1) coding the genome of each song;
(2) listen to other users’ radio stations
(Friends, Neighbors, Groups)
e.g. Friend Network (Fb);
Reputation Network (Ebay)
my proposal
 Recommendation based
on novelty.
 Novelty delivering based
on users attributes and
in the social graph
 Surprise response as a
proxy of the Novelty to
design the framework.
Literature Review
topics of research
 Novelty delivering.
Bridging ties
 Dimensions implied on novelty.
Emotional response (Surprise)
Tie strength (between receptor and source of information)
Homophily (similarities)
Centrality (structural location in the social network)
Literature Review
novelty delivering
Bridging Ties
 The Strength of Weak
Ties (Granovetter 1973)
 All bridges are weak ties.
Not all weak ties are
 Strong ties can be a bridge
if such ties do not share
ties with other individuals
of the same clique.
How to deliver novelty?
Literature Review
novelty delivering
Bridging Ties
 Structural Holes
(Burt 1992)
 Tie strength does not determine
the information potential
brought by a bridging tie.
 Structural holes linked by actors
determine the information
 Ties established by nonredundant links between actors.
 Weak ties and Structural holes
Structural Holes and Weak Ties
(Burt 1992)
(McEvily et al. 1999)
Literature Review
dimensions implied on novelty
Emotional response
Can I predict novelty?
 Ten primordial emotions (DES scale of Izard)
(Izard 1991)
 Emotions start with a process of cognitive
appraisal (Finkenauer et al. 1998).
 Novelty is one fundamental type of appraisal
(e.g., Scherer 1984; Smith and Ellsworth 1987).
 Surprise is a specific consequence of the
appraisal of novelty (Finkenauer et al. 1998).
Literature Review
dimensions implied on novelty
Measuring tie strength
What makes a tie be strong?
 Amount of time, intimacy, intensity and
reciprocal services (Granovetter 1973).
 Closeness
(Marsden et al. 1984).
 Emotional support
(Wellman and Wortley 1990).
 Intensity and valence
(Petrosky 2011).
Literature Review
dimensions implied on novelty
Why some weak ties are not bridges?
 Demographic and Attitudinal similarities
 Status homophily
 Background factors (economic status), gender, religion
and ethnicity (McPherson et al. 2001).
 Attitudinal homophily
 Perceived Homophily Measure (McCroskey et al. 1975;
Literature Review
dimensions implied on novelty
 Cognitive similarities based on:
 Music genres
Reflective and Complex, Intense and Rebellious, Upbeat
and Conventional, and Energetic and Rhythmic (Rentfrow
and Gosling 2003).
 Emotional reaction to music genres.
 Similarities on information interests. Similarities on
emotional reaction to the information accessed.
Equal preferences on content posted (survey).
Literature Review
dimensions implied on novelty
Can I predict structural location?
 Degree; betweeness; closeness
(Freeman 1979)
 Centrality and information flow
(Borgatti et al. 2009;
Mori et al. 2010)
 Centrality and friendship network
Afuah 2013)
(Opshal 2010;
Research questions
 Does surprise define bridging ties?
 Can similarities in individual attributes and
structural location in the network determine the
stimulus of surprise?
 H1 – Is more likely that an individual become
surprised by a weak tie than by a strong tie.
 H2 – The non redundancy between ties is
predictor of surprise.
 H3 – The degree of homophily justifies the
conditions that make someone weakly tied to
another person acting as a bridge.
 H4 – Users' popularity is independent of the
novelty appraisal by the receptors.
Research Methods
 Survey
 Emotional response, particularly on surprise
 Ties strength
 Homophily
 Statistics (Logistic regression; Multivariate regression;
Mann-Whitney test)
Research Methods
 NodeXl
 Centrality variables (degree; betweeness; closeness)
Graph 1 - Emotional reaction to
information sharing
Graph 2 – Friendship network
Desired contribution
 Emotional reaction as a relevant property for
social networks analysis.
 A methodology that identifies bridging ties and
characterizes the delivering of novelty based in
the stimulus of surprise.
 A framework for recommendation systems
based on weak ties as recommenders of
surprising information or of new perspectives.
 Comments are welcome…
 Thank you.
Carlos Figueiredo