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Network analysis (partial correlations)

Psychometric network analysis draws a Gaussian graphical model whose edges are significance-thresholded partial correlations, laid out as a circular network with centrality indices.

What is Network analysis (partial correlations)?

A partial-correlation network shows which variable pairs remain associated after conditioning on every other variable — marginal correlations that vanish under conditioning draw no edge. Two estimators: EBICglasso (default) runs the graphical lasso over a λ path and picks the model by EBIC (γ tunes the sparsity preference), shrinking small edges to exactly zero; the pcor alternative computes unregularized partial correlations from the inverse correlation matrix, t-tests each (df = n − p), and keeps edges surviving Benjamini-Hochberg FDR at the chosen α.

Green edges are positive partial correlations, red negative; width tracks magnitude.

Centrality: strength (Σ|weights| at a node) and expected influence (signed sum — better when negative edges exist). Closeness/betweenness are omitted deliberately; the field increasingly discourages them for psychological networks.

When should I use Network analysis (partial correlations)?

  • Symptom / item networks in psychopathology and personality research.
  • Exploring conditional-dependence structure among many numeric variables.

What data does it need?

≥ 3 numeric columns + estimator (EBICglasso with γ, or pcor with FDR α).

What does it report?

Circular network plot, edge count / sparsity, strength + expected-influence centrality table.

What does it assume?

  • Multivariate normality (Gaussian graphical model).
  • n comfortably above the node count (df = n − p per edge test).
  • Thresholding controls false edges — absence of an edge is not proof of independence.

How do I interpret the result?

High-strength nodes are the most connected; an edge is a conditional association, not causation. Networks are unstable in small samples — replicate before interpreting fine structure.

See also

References

  • Epskamp, Borsboom & Fried (2018). Estimating psychological networks and their accuracy. BRM 50.
  • Drton & Perlman (2004). Model selection for Gaussian concentration graphs. Biometrika 91.