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Correlation

Principal component analysis

Decomposes a set of correlated variables into fewer components, from their correlation matrix.

Variables

  • VariablesContinuous · Ordinal — at least 3

Options

  • Components retained (0 = all)

What it reports

Eigenvalue, share of variance explained and loadings for each component; KMO and Bartlett test.

scipy · Open the accuracy report

When does this apply?

For decomposing at least three interrelated quantitative variables into fewer components; the decomposition runs on their correlation matrix. No hypothesis is tested: the output is the eigenvalues, the proportions of variance explained, the loadings, KMO and Bartlett’s test of sphericity. How many components to retain is the researcher’s decision — all are shown by default and the software imposes no cutoff such as “eigenvalue > 1”. With two variables there is nothing to decompose: Correlation analysis covers that case.

Related analyses

Research articleOAK-compliant article