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A DIRICHLET-MULTINOMIAL APPROACH TO BELIEF PROPAGATION
THE POWER OF CERTAINTY
Dhivya Eswaran* CMU
Stephan Guennemann TUM
Christos Faloutsos CMU
PROBLEM
MOTIVATION
NETCONF
GUARANTEES
EXPERIMENTSEswaran, Guennemann & Faloutsos
PROBLEM
ADS PLACEMENT
ALICE
BOB
CAROL
SMITH
RECOMMENDATION
ALICE
BOB
CAROL
SMITH
JOHN
THE POWER OF CERTAINTY A DIRICHLET-MULTINOMIAL MODEL FOR BELIEF PROPAGATION
Eswaran, Guennemann & Faloutsos
GRAPH LABELING / NODE CLASSIFICATIONEXPERIMENTS
4
GIVEN
‣ a graph of nodes & edges
‣ labels for a few nodes
‣ label compatibility
FIND
‣ labels of all nodes
ALICE BOB
CAROL
SMITH
JOHN
H0.8 0.2
0.2 0.8
H0.2 0.7 0.1
0.7 0.2 0.1
0.1 0.1 0.8
THE POWER OF CERTAINTY A DIRICHLET-MULTINOMIAL MODEL FOR BELIEF PROPAGATION
Eswaran, Guennemann & Faloutsos
NODE CLASSIFICATION IS HARDEXPERIMENTS
5
SMITH
4 x
1 x
JOHN
30 x
15 x
Who is more likely to buy an Android phone?
“Higher fraction of android friends”
“Higher number of android friends”
PROBLEM
MOTIVATION
NETCONF
GUARANTEES
EXPERIMENTSEswaran, Guennemann & Faloutsos
MOTIVATION
THE POWER OF CERTAINTY A DIRICHLET-MULTINOMIAL MODEL FOR BELIEF PROPAGATION
Eswaran, Guennemann & Faloutsos
CLASSIFICATION BY “PROPAGATION”EXPERIMENTS
7
INITIALIZE:
‣ Set nodes to random/given values.
PROPAGATE:
‣ Update each node’s value based on the values of its neighbors.
CONVERGENCE:
‣ If no value changes, terminate.
‣ Else continue propagation.
SMITH
ALICE
BOB
CAROL
Q1. What are values here?
Q2. How are they updated?
THE POWER OF CERTAINTY A DIRICHLET-MULTINOMIAL MODEL FOR BELIEF PROPAGATION
Eswaran, Guennemann & Faloutsos
“BELIEF” PROPAGATIONEXPERIMENTS
8
SMITH
ALICE
BOB
CAROL
A1. Values : beliefs
A2. Update : 2 stages
(probability vectors)
(i) Each neighbor sends a message
(ii) Node updates its belief based on messages
[0.4, 0.6]
[0.5, 0.5]
[0.8, 0.2]
[0.73, 0.27] bu(i) eu(i)Y
v2N (u)
mvu(i)
mvu(i) kX
j=1
H(i, j)ev(j)Y
v2N (v)\u
mwu(i)
DETAILS!
THE POWER OF CERTAINTY A DIRICHLET-MULTINOMIAL MODEL FOR BELIEF PROPAGATION
Eswaran, Guennemann & Faloutsos
BP LEADS TO COUNTER-INTUITIVE RESULTSEXPERIMENTS
9
Who is more likely to buy an Android phone?
110 x
100 xJOHN
13 x
3 xSMITH
INTUITION
BP
THE POWER OF CERTAINTY A DIRICHLET-MULTINOMIAL MODEL FOR BELIEF PROPAGATION
Eswaran, Guennemann & Faloutsos
MAIN IDEAEXPERIMENTS
10
“belief distributions” as values
10.5
prob
abilit
y
0
belief / leaning(ratio of android : apple neighbors)
certainty / confidence
(absolute count of
neighbors)
PROBLEM
MOTIVATION
NETCONF
GUARANTEES
EXPERIMENTSEswaran, Guennemann & Faloutsos
NETCONF
THE POWER OF CERTAINTY A DIRICHLET-MULTINOMIAL MODEL FOR BELIEF PROPAGATION
Eswaran, Guennemann & Faloutsos
NODE CLASSIFICATION WITH CERTAINTYEXPERIMENTS
12
GIVEN
‣ a graph of nodes & edges
‣ belief distributions for a few nodes
‣ label compatibility
FIND
‣ belief distributions of all nodes
SUBJECT TO
‣ theoretically-grounded algorithm
‣ fast & scalable implementation
H0.8 0.2
0.2 0.8
ALICE BOB
CAROL
SMITH
JOHN
THE POWER OF CERTAINTY A DIRICHLET-MULTINOMIAL MODEL FOR BELIEF PROPAGATION
Eswaran, Guennemann & Faloutsos
DIRICHLET BELIEF DISTRIBUTIONS (1/2)EXPERIMENTS
13
2D Dirichlet distribution (Beta distribution)
p(x;↵+ 1,� + 1) / x
↵(1� x)�
Belief/Leaning : ↵+ 1
↵+ � + 2
BACKGROUND
# #
THE POWER OF CERTAINTY A DIRICHLET-MULTINOMIAL MODEL FOR BELIEF PROPAGATION
Eswaran, Guennemann & Faloutsos
DIRICHLET BELIEF DISTRIBUTIONS (2/2)EXPERIMENTS
14
Certainty:↵+ �
EXTENDS TO ANY NUMBER OF DIMENSIONS!!
Image source: UBC Wiki
BACKGROUND
Example: 3 dimensions (talkative / silent / confused)
THE POWER OF CERTAINTY A DIRICHLET-MULTINOMIAL MODEL FOR BELIEF PROPAGATION
Eswaran, Guennemann & Faloutsos
MULTINOMIAL MESSAGE DISTRIBUTIONSEXPERIMENTS
15
BP belief update rule
parameters of belief distribution
parameters of message distribution
NETCONF belief update rule
MULTINOMIAL DISTRIBUTION!
DIRICHLET DISTRIBUTION
DETAILS!
bu(i) eu(i)Y
v2N (u)
mvu(i)
bu eu +X
v2N (u)
mvu
THE POWER OF CERTAINTY A DIRICHLET-MULTINOMIAL MODEL FOR BELIEF PROPAGATION
Eswaran, Guennemann & Faloutsos
MESSAGES FROM BELIEFSEXPERIMENTS
16
JOHNSMITH
(a, b)
(a, b)
perfect homophily
(b, a)
perfect heterophily
M =k
k � 1
✓H� 1
k
◆+
(0, 0)
no network effects
THE POWER OF CERTAINTY A DIRICHLET-MULTINOMIAL MODEL FOR BELIEF PROPAGATION
Eswaran, Guennemann & Faloutsos
NETCONF BELIEF & MESSAGE UPDATE RULESEXPERIMENTS
17
message update
belief update
M
bu eu +X
v2N (u)
mvu
mvu M
0
@eu +X
v2N (v)\u
mwu
1
A
muvbu
THE POWER OF CERTAINTY A DIRICHLET-MULTINOMIAL MODEL FOR BELIEF PROPAGATION
Eswaran, Guennemann & Faloutsos
NETCONF MATRIX BELIEF UPDATEEXPERIMENTS
18
modulation
B E+ (ABM�DBM2)(I�M2)�1
prior belief distribution
final belief distribution
~~ ~~~~
diagonal degreeadjacency
~~ ~~~~ ~~
~ ~~ ~
~ ~~ ~
PROBLEM
MOTIVATION
NETCONF
GUARANTEES
EXPERIMENTSEswaran, Guennemann & Faloutsos
GUARANTEES
THE POWER OF CERTAINTY A DIRICHLET-MULTINOMIAL MODEL FOR BELIEF PROPAGATION
Eswaran, Guennemann & Faloutsos
KEY THEORETICAL QUESTIONSEXPERIMENTS
20
UNIQUENESS
CONVERGENCE
Is the steady state solution unique?
Can we predict convergence?
THE POWER OF CERTAINTY A DIRICHLET-MULTINOMIAL MODEL FOR BELIEF PROPAGATION
Eswaran, Guennemann & Faloutsos
NETCONF HAS CLOSED-FORM SOLUTIONEXPERIMENTS
21
ITERATIVE UPDATE
CLOSED FORM
Roth’s Column Lemma
DETAILS!
vec(B) =⇣I� (MM)T ⌦A+ (M2M)T ⌦D
⌘�1vec(E)
B E+ (ABM�DBM2)(I�M2)�1
THE POWER OF CERTAINTY A DIRICHLET-MULTINOMIAL MODEL FOR BELIEF PROPAGATION
Eswaran, Guennemann & Faloutsos
PRECISE CONVERGENCE GUARANTEES
22
GRAPH STRUCTURE LABEL COMPATIBILITY
CLOSED FORM
NECESSARY &
SUFFICIENT CONDITION
DETAILS!
⇢⇣(MM)T ⌦A+ (M2M)T ⌦D
⌘< 1
vec(B) =⇣I� (MM)T ⌦A+ (M2M)T ⌦D
⌘�1vec(E)
GUARANTEES
THE POWER OF CERTAINTY A DIRICHLET-MULTINOMIAL MODEL FOR BELIEF PROPAGATION
Eswaran, Guennemann & Faloutsos
KEY THEORETICAL GUARANTEESEXPERIMENTS
23
CLOSED-FORM
CONVERGENCE
Closed-form solution and unique fixed point!
Necessary and sufficient conditions for convergence!
PROBLEM
MOTIVATION
NETCONF
GUARANTEES
EXPERIMENTSEswaran, Guennemann & Faloutsos
EXPERIMENTS
THE POWER OF CERTAINTY A DIRICHLET-MULTINOMIAL MODEL FOR BELIEF PROPAGATION
Eswaran, Guennemann & Faloutsos
KEY QUESTIONS FOR EXPERIMENTSEXPERIMENTS
25
EFFECTIVENESS
SCALABILITY
INTERPRETABILITY
Improves accuracy & precision?
Fast and scalable?
Are final results interpretable?
THE POWER OF CERTAINTY A DIRICHLET-MULTINOMIAL MODEL FOR BELIEF PROPAGATION
Eswaran, Guennemann & Faloutsos
DATAEXPERIMENTS
26
POLBLOGS
2 classes
1.5K nodes, 19K edges
DBLP
4 classes
28K nodes, 67K edges
POKEC
10 classes
1.6M nodes, 30M edges
THE POWER OF CERTAINTY A DIRICHLET-MULTINOMIAL MODEL FOR BELIEF PROPAGATION
Eswaran, Guennemann & Faloutsos
NETCONF IS ACCURATE AND PRECISEEXPERIMENTS
27
HIGHER ACCURACY %
DATASET BP NETCONF
POLBLOGS 91.38 92.40
DBLP 76.26 81.89
POKEC 73.78 75.02
BETTER PRECISION
Ideal
THE POWER OF CERTAINTY A DIRICHLET-MULTINOMIAL MODEL FOR BELIEF PROPAGATION
Eswaran, Guennemann & Faloutsos
NETCONF IS FAST AND SCALABLEEXPERIMENTS
28
30M edges in ~7 seconds!
Linear scaling with graph size
THE POWER OF CERTAINTY A DIRICHLET-MULTINOMIAL MODEL FOR BELIEF PROPAGATION
Eswaran, Guennemann & Faloutsos
NETCONF GIVES INTERPRETABLE RESULTSEXPERIMENTS
29
AUTHOR H-index
Michael J Carey 48
Rakesh Agrawal 96
Jiawei Han 139
Hamid Pirahesh 40
David J Dewitt 81
Serge Abiteboul 77
AUTHOR H-index
Jiawei Han 139
Annie W Shum -
Werner Keibling -
Xiaofang Zhou 36
Bertram Ludascher 45
Amarnath Gupta -
TOP DATABASES AUTHORS IN DBLP
Many papers &high H1 indices!
BPNETCONF
THE POWER OF CERTAINTY A DIRICHLET-MULTINOMIAL MODEL FOR BELIEF PROPAGATION
Eswaran, Guennemann & Faloutsos
KEY EXPERIMENTAL FINDINGSEXPERIMENTS
30
EFFECTIVENESS
SCALABILITY
INTERPRETABILITY
Improves accuracy & precision!
Scales linearly with graph size!
Certainty scores reflect intuition!
THE POWER OF CERTAINTY A DIRICHLET-MULTINOMIAL MODEL FOR BELIEF PROPAGATION
Eswaran, Guennemann & Faloutsos
SUMMARY: NETCONFSUMMARY
31
✓Theoretically grounded
✓Closed-form solution
✓Convergence guarantees
✓Improved performance
✓Fast and scalable
✓Interpretable results
Questions? [email protected]