Correlation | Null hypothesis | Null model |
---|---|---|
Activity correlation | The activities of users in a type of communication are unrelated to those in other types of communication. | Hypergeometric model (Nicosia and Latora 2015) |
Role correlation | The roles of users in a type of communication (i.e., their positions in a type of communication network) are unrelated to those in other communication. | Independent multilayer node-permutation model (Croft et al. 2011) |
Link overlap | Users’ interconnections in one type of communication are unrelated to those in other communication. | Independent multilayer configuration model (Paul and Chen 2016) |
Link-strength correlation | The strength/frequency of interactions between two users in one type of communication is unrelated to those in other communication. | Independent directed-weight reshuffling model (Opsahl et al. 2008) |