เปรียบเทียบวิธี

	E-I Index	การวิเคราะห์เครือข่ายทางสังคม
สาขาวิชา	Sociology	การวิเคราะห์เครือข่าย
ตระกูล	Process / pipeline	Machine learning
ปีกำเนิด	1988	1934 (sociometry); 1994 (modern formalization)
ผู้ริเริ่ม	David Krackhardt & Robert Stern	Moreno, J.L.; formalized by Wasserman & Faust
ประเภท	Index of the relative balance of between-group versus within-group ties	Structural/relational analysis framework
แหล่งต้นตำรับ	Krackhardt, D., & Stern, R. N. (1988). Informal networks and organizational crises: An experimental simulation. Social Psychology Quarterly, 51(2), 123–140.	Wasserman, S. & Faust, K. (1994). Social Network Analysis: Methods and Applications. Cambridge University Press. ISBN: 978-0-521-38707-1
ชื่อเรียกอื่น	EI index, external-internal index, Krackhardt-Stern E-I ratio, E/I ratio	SNA, network analysis, sociometric analysis, relational analysis
ที่เกี่ยวข้อง	5	5
สรุป	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.	Social Network Analysis (SNA) is a structural method that maps and measures relationships and flows between people, groups, organizations, or other entities modeled as nodes connected by ties (edges). Rather than focusing on individual attributes, SNA reveals how the pattern of connections shapes behavior, influence, information flow, and outcomes within a system.