Confronta i metodi

	E-I Index	Dyadic Analysis	Homophily Analysis
Campo	Sociology	Sociology	Sociology
Famiglia	Process / pipeline	Regression model	Process / pipeline
Anno di origine	1988	1981	1954 (concept); 2001 (synthesis)
Ideatore	David Krackhardt & Robert Stern	Holland & Leinhardt (p1); Kenny (Social Relations Model)	Lazarsfeld & Merton (concept); McPherson, Smith-Lovin & Cook (synthesis)
Tipo	Index of the relative balance of between-group versus within-group ties	Analysis of the dyad as the unit, decomposing relational effects	Measurement of similarity-based tie formation
Fonte seminale	Krackhardt, D., & Stern, R. N. (1988). Informal networks and organizational crises: An experimental simulation. Social Psychology Quarterly, 51(2), 123–140.	Holland, P. W., & Leinhardt, S. (1981). An exponential family of probability distributions for directed graphs. Journal of the American Statistical Association, 76(373), 33–50.	McPherson, M., Smith-Lovin, L., & Cook, J. M. (2001). Birds of a feather: homophily in social networks. Annual Review of Sociology, 27, 415–444.
Alias	EI index, external-internal index, Krackhardt-Stern E-I ratio, E/I ratio	dyad analysis, dyadic data analysis, social relations model, dyad census	homophily measurement, assortative mixing analysis, birds-of-a-feather analysis, tie-similarity analysis
Correlati	5	4	4
Sintesi	The external-internal (E-I) index, introduced by Krackhardt and Stern, measures the extent to which the ties of a group point outward to other groups versus inward to its own members. It is the number of between-group (external) ties minus the number of within-group (internal) ties, divided by the total number of ties. Ranging from −1 (all ties internal, perfect insularity) to +1 (all ties external), it is a compact summary of homophily and group closure that can be computed for a whole network, for each group, or for each node.	Dyadic analysis treats the dyad — the pair of actors and the relation between them — as the unit of analysis, separating the relational outcome into what each actor brings to all their relationships and what is unique to the specific pair. It spans the descriptive dyad census of network analysis and statistical frameworks such as Holland and Leinhardt's p1 model and Kenny's Social Relations Model, all of which respect the structural non-independence inherent in relational data.	Homophily analysis quantifies the tendency of similar individuals to form ties — the principle that 'birds of a feather flock together'. It compares the rate at which people connect with others who share an attribute (race, gender, age, education, attitudes) against what would be expected by chance, distinguishing the homophily that arises merely from group sizes from the genuine, behavior-driven preference for similar others.