11 network experiments and interventions
TRANSCRIPT
Network Experiments & Interventions
1) Assessing Peer Effects1) Manipulate networks to force connectivity to be exogenous
1) Roommate studies2) Natural Experiments
2) Manipulate exposure over existing networks1) Popularity2) Voter Turnout
2) Interventions: Use networks to affect change1) Valente’s 4 elements of network intervention2) Exemplars
3) Network interference in “standard” experiments4) What we’re ignoring: small group stuff
1) network exchange experiments2) Transmission evolution experiments
Network Experiments & InterventionsIntro
Shalizi & Thomas: PI is *generally* confounded
General fear of confounding by unobserved selection features has pushed interest in network experiments. How to make a social relation exogenous?
Roommates assigned randomly within gender, & self-reported smoking, study-style & messiness.
No evidence of pair-similarity based on this sorting (i.e. all evidence suggests randomness is real)
Network Experiments & InterventionsExogenous networks (W)
Assume that one’s one GPA is a function of own ability & peer ability and GPA
Network Experiments & InterventionsExogenous networks (W)
Assume that one’s one GPA is a function of own ability & peer ability and GPA…results suggest a positive effect.
Similar effects on social outcomes (joining a fraternity, etc.)…
Network Experiments & InterventionsExogenous networks (W)
Network Experiments & InterventionsExogenous networks (W)
Note follow-up work (by Salganik & Watts) suggests the effects are weak and not long lasting
Network Experiments & InterventionsExogenous networks (W)
Network Experiments & InterventionsExogenous networks (W)
SEPTEMBER 2010 VOL 329 SCIENCE
Network Experiments & InterventionsExogenous networks (W): Issues with experimental assignment
Sharique Hassan
Network Experiments & InterventionsExogenous networks (W): Issues with experimental assignment
Sharique Hassan
Network Experiments & InterventionsExogenous networks (W): Issues with experimental assignment
Sharique Hassan
Network Experiments & InterventionsExogenous networks (W): Issues with experimental assignment
Sharique Hassan
Network Experiments & InterventionsExogenous networks (W): Issues with experimental assignment
Sharique Hassan
Network Experiments & InterventionsExogenous networks (W): Issues with experimental assignment
Sharique Hassan
Network Experiments & InterventionsExogenous networks (W): Issues with experimental assignment
Sharique Hassan
Network Experiments & InterventionsExogenous Behavior (Y)
4 types of interventions:1) Individuals
1) Finding opinion leaders or flow blocking nodes that play a key role in the network process. usually some centrality score, or an adaptive algorithm. Here highlighted “keyplayer” nodes.
2) Segmentation3) Induction4) Alteration
Network Experiments & InterventionsExogenous Behavior (Y)
4 types of interventions:1) Individuals2) Segmentation
1) Use communities to break the groups into parts, treat some use others as controls.
3) Induction4) Alteration
Network Experiments & InterventionsExogenous Behavior (Y)
4 types of interventions:1) Individuals2) Segmentation3) Induction
1) Enhance relations & communication4) Alteration
Network Experiments & InterventionsExogenous Behavior (Y)
4 types of interventions:1) Individuals2) Segmentation3) Induction4) Alteration
1) Programs that seek to change the shape of the network, add/remove ties or nodes
Network Experiments & InterventionsExogenous Behavior (Y)
Network Experiments & InterventionsExogenous Behavior (Y)
Exploit the “Friendship Paradox” idea…