Ego Network Analysis — Personal Network Analysis

You need two levels of data for every focal respondent (ego): first, a list of their contacts (alters) collected via a name-generator question; second, information on which pairs of those alters are connected to each other (alter-alter ties), typically gathered with a name-interpreter follow-up. Without the alter-alter data you can measure network size but cannot compute density, constraint, or structural holes.

Burt's constraint index measures how tightly interconnected an ego's contacts are. A high constraint score means the ego's alters are all connected to each other, so the ego receives the same information from multiple redundant sources and has little brokerage power. A low constraint score indicates many structural holes — the ego bridges disconnected groups and gains informational diversity and brokerage advantage. The index is computed using Burt's formula over the ego graph adjacency matrix.

Whole-network (sociocentric) analysis requires complete relational data among all members of a defined population, and computes global metrics such as betweenness centrality across the entire network. Ego network analysis requires only each respondent's local neighbourhood — alters and alter-alter ties — making it practical for large or boundary-spanning populations where complete network data are infeasible to collect. The trade-off is that ego-level metrics are locally bounded and cannot reveal global network topology.

With fewer than 20 egos, ego network metrics become unstable and inferential analysis is unreliable. The recommended fallback is descriptive statistics: report network size and density distributions as summaries rather than inputs to regression or comparison tests, and treat findings as exploratory pending a larger sample.