SLIDE 1 Mix Mixin ing P g Patterns i in S Social N l Networks
Leto Peel Université catholique de Louvain @PiratePeel
SLIDE 2 Bird irds s of
a feat feather. her... …fl floc
ether her
SLIDE 3 Visi Visibi bilit ity y an and ran ranking of
ies
Karimi et al. “Homophily influences ranking of minorities in social networks” Scientifjc Reports (2018)
heterophily random homophily minorities
minorities under-represented
SLIDE 4 Two wo ques questions. s...
- 1. Can we detect heterogeneities in mixing within a network?
- 2. Can we compare mixing patterns between networks?
SLIDE 5
Mixin ixing in in so socia cial networ works
SLIDE 6
General eralis isat ation ion, , not rul rules! es!
SLIDE 7 Mi Mixin xing pat pattern erns s in in netwo work rks
Newman “Mixing patterns in networks” Phys. Rev. E (2003)
assortative disassortative
SLIDE 8
egh = ag = bg = Assume for now, that the network is undirected. i.e., ag == bg Mixing matrix
SLIDE 9
Asso Assort rtat ativit ivity y is is co correl rrelat ation ion acro ross s edges
SLIDE 10 Asso Assort rtat ativit ivity y is is co correl rrelat ation ion acro ross s edges
Anscombe, "Graphs in Statistical Analysis". American Statistician (1973)
SLIDE 11 All these hese net etwork works have have ass assort rtat ativit ivity y r=0 =0
Peel, Delvenne, Lambiotte, "Multiscale mixing patterns in networks". PNAS (2018)
SLIDE 12 Can Can we we meas measure ure as asso sort rtat ativit ivity y loc
y?
SLIDE 13
Time ime se series ries an anal alysi ysis
The mean is only representative of the data around the middle of the time series Time series Mean
SLIDE 14
Time ime se series ries an anal alysi ysis
Exponentially weighted mean Recent points are more relevant
SLIDE 15 Asso sort rtat ativit ivity y is is the aut autoc
relation of f a a ran random
walk
g h Random walk Sequence of node attributes
SLIDE 16 Asso sort rtat ativit ivity y is is the aut autoc
relation of f a a ran random
walk
g h Random walk Sequence of node attributes stationary distribution proportional to the degree
SLIDE 17 Asso sort rtat ativit ivity y is is the aut autoc
relation of f a a ran random
walk
g h Random walk Sequence of node attributes stationary distribution proportional to the degree Recovers Newman’s assortativity
SLIDE 18 Random walk with restart
“Local calise” se” us usin ing random
walk wit with rest restart art
SLIDE 19 Random walk with restart stationary distribution (Personalised PageRank)
“Local calise” se” us usin ing random
walk wit with rest restart art
SLIDE 20 Random walk with restart stationary distribution (Personalised PageRank)
“Local calise” se” us usin ing random
walk wit with rest restart art
Re-weight nodes:
SLIDE 21
Newman’s assortativity (global) Single node (local)
SLIDE 22 Iden entify fy loc
pattern rns. s...
Random mixing assortative + disassortative
SLIDE 23 Fac aceboo book 100 100 – – re resid siden ence ce
Peel, Delvenne, Lambiotte, "Multiscale mixing patterns in networks". PNAS (2018)
SLIDE 24 Fac aceboo book 100 100 – – re resid siden ence ce
Peel, Delvenne, Lambiotte, "Multiscale mixing patterns in networks". PNAS (2018)
SLIDE 25
Can Can we we co comp mpare are assort assortat ativ ivity acro ross s network rks? s?
SLIDE 26 Co Correl rrelat ation ion of
binary ary vari ariabl able e (Φ3coefficie
SLIDE 27 Sampl Samples es in a a net etwor work are are not in indepe penden ent!
Two samples,
SLIDE 28 Ful ull ran range of f ass assort rtat ativit ivity y is is oft
attain ainab able
Assortativity is constrained by degree distribution and proportion of nodes of each type
Cinelli, Peel, Iovanella, Delvenne, “Network constraints on the mixing patterns of binary metadata” in prep.
SLIDE 29 We We also so in inherit herit issu issues es from from the he Φ3co 3coeffic fficien ent
egh = ag = bg = Mixing matrix For r =1, we require that ag = bg = 0.5
Cureton, "Note on Φ/Φmax". Psychometrika (1959) Davenport, El-Sanhurry, “Phi/Phimax: Review and Synthesis” Educational and psychological measurement (1991)
SLIDE 30 We We also so in inherit herit issu issues es from from the he Φ3co 3coeffic fficien ent
egh = ag = bg = Mixing matrix For r =1, we require that ag = bg = 0.5 For r =-1, we require that ai = bj = 0.5 aj = bi = 0.5
Cureton, "Note on Φ/Φmax". Psychometrika (1959) Davenport, El-Sanhurry, “Phi/Phimax: Review and Synthesis” Educational and psychological measurement (1991)
SLIDE 31
Smith (-0.006, 0.811) Wellesley (-0.009, 0.368) Stanford (-0.988, 1.000)
Ord Order er these se net etwork works s by by as asso sort rtat ativit ity
SLIDE 32
Smith r=0.025 (-0.006, 0.811) Wellesley r=0.246 (-0.009, 0.368) Stanford r=0.057 (-0.988, 1.000)
Ord Order er these se net etwork works s by by as asso sort rtat ativit ity
SLIDE 33
Smith r=0.025 (-0.006, 0.811) Wellesley r=0.246 (-0.009, 0.368) Stanford r=0.057 (-0.988, 1.000)
Ord Order er these se net etwork works s by by as asso sort rtat ativit ity
SLIDE 34
SLIDE 35
Can we we st standard ardis ise e assort assortat ativ ivity?
SLIDE 36
SLIDE 37
SLIDE 38 What What does
he norm
sation ion me mean an?
Maintains the ratio between diagonal and off-diagonal elements egh = Mixing matrix
SLIDE 39
SLIDE 40 How How does
his comp
are to
Newman’s ’s assort ssortat ativity? y?
Mixing matrix Vary two parameters:
- a0 : proportion of edges incident on minority group
- e00 : proportion of minority in-group edges
SLIDE 41
balanced groups y=x increasingly imbalanced
SLIDE 42 How How does
his comp
are to
Newman’s ’s assort ssortat ativity? y?
SLIDE 43
Ord Order er these se net etwork works s by by (n (normal rmalis ised ed) ) as assor sortat ativit ity
Smith r=0.325 Stanford r=0.057 Wellesley r=0.789
SLIDE 44 Phy Physic ics Col
aborat ration Network rk
SLIDE 45 Phy Physic ics Col
aborat ration Network rk
SLIDE 46 Summary Summary
Assortativity plays an important role in understanding the
- rganisation of complex networks
Mu Multiscal ale mixing: detect heterogeneous mixing patterns in a network Normalised as assortati ativity: compare mixing patterns across networks? #methodsmatter
SLIDE 47 Advertis isemen ement
https://wwcs2020.github.io/
#swisscheesearemadeofthese
SLIDE 48 In col
aborat ration ion wi with...
Renaud Lambiotte Jean-Charles Delvenne Matteo Cinelli Antonio Iovanella Fariba Karimi Mauro Faccin
Contact: leto.peel@uclouvain.be @PiratePeel
Peel, Delvenne, Lambiotte, "Multiscale mixing patterns in networks". PNAS (2018) Cinelli, Peel, Iovanella, Delvenne, “Network constraints on the mixing patterns of binary metadata” in prep. Cinelli, Faccin, Karimi, Peel, “Gender mixing preferences across networks” in prep.