방법 비교

	Krackhardt Hierarchy Measures	E-I Index
분야	Sociology	Sociology
계열	Process / pipeline	Process / pipeline
기원 연도	1994	1988
창시자	David Krackhardt	David Krackhardt & Robert Stern
유형	Set of four graph-theoretic indices of how hierarchical a network is	Index of the relative balance of between-group versus within-group ties
원전	Krackhardt, D. (1994). Graph theoretical dimensions of informal organizations. In K. M. Carley & M. J. Prietula (Eds.), Computational Organization Theory (pp. 89–111). Lawrence Erlbaum Associates.	Krackhardt, D., & Stern, R. N. (1988). Informal networks and organizational crises: An experimental simulation. Social Psychology Quarterly, 51(2), 123–140.
별칭	Krackhardt GTD, graph-theoretic dimensions of hierarchy, Krackhardt connectedness-hierarchy-efficiency-LUB, out-tree hierarchy measures	EI index, external-internal index, Krackhardt-Stern E-I ratio, E/I ratio
관련	5	5
요약	Krackhardt's graph-theoretic dimensions provide four indices that together measure how closely a directed network approximates a pure hierarchy — formally, an out-tree. The dimensions are connectedness (is everyone linked?), hierarchy (are ties asymmetric, i.e., non-reciprocated?), efficiency (are there no redundant ties?), and least upper bound (does every pair share a common superior?). Each is scaled from 0 to 1, and a network scoring 1 on all four is a perfect hierarchy.	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.