social networks

Question 1

reciprocity

Answer 1

= a measure of number of bi-directional links
e.g. if A trusts B, but N doesn’t trust A, then the link is one-directional

–> the lager the percentage of bi-directional (reciprocal) relations in a network, the higher the reciprocity

Question 2

degree

1. in-degree-centrality
2. out-degree-entrality

Answer 2

= degree of a node is measure of its connectedness; tells you how many links this node has to other nodes in network

1. reflecting total number of links pointing TOWARDS a single good
2. reflecting the total number of links LEAVING a single good

–> sum of in-degree and out-degree is equal to (overall) degree

Question 3

density

Answer 3

= indicates what percentage of possible connections actually exist in network

eg. if all kids in class are connected through FB –> density = 1

Question 4

transitivity

Answer 4

= measures in how far two nodes (A,C) are connected to each other if they are both connected to a third node (B)

Question 5

modularity

Answer 5

= measure used to determine in how far a network consists of smaller modules (clusters, groups, commutes)

–> networks with high modularity –> strong connections within a module but few/ weak connections between modules

Question 6

small-world index

–> small-world phenomenon

Answer 6

= there exists a short path between any two randomly chosen nodes in a network of arbitrary size
(only 5 people)