手法を比較

	E-I Index	Dyadic Analysis
分野	Sociology	Sociology
系統	Process / pipeline	Regression model
提唱年	1988	1981
提唱者	David Krackhardt & Robert Stern	Holland & Leinhardt (p1); Kenny (Social Relations Model)
種類	Index of the relative balance of between-group versus within-group ties	Analysis of the dyad as the unit, decomposing relational effects
原典	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.
別名	EI index, external-internal index, Krackhardt-Stern E-I ratio, E/I ratio	dyad analysis, dyadic data analysis, social relations model, dyad census
関連	5	4
概要	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.