polychoric
Meaning
relating to or denoting a correlation coefficient used in statistics for estimating the correlation between two theorized normally distributed continuous variables from observed ordinal data.
Structure
Usage
the researcher employed a polychoric correlation to analyze the ordinal survey responses.
polychoric correlation matrices are essential for structural equation modeling with categorical variables.
the assumption underlying the polychoric correlation is that a latent continuous variable follows a normal distribution.
Etymology
the term polychoric is a modern scientific compound, primarily used in statistics. it is formed from the greek combining form 'poly-', meaning 'many', and 'choric', which is derived from 'khoros', referring to a chorus or group. the original greek 'khoros' evoked the idea of an ensemble performing in unison, a concept that evolved metaphorically to represent any grouped or aggregated set. in constructing 'polychoric', this sense of 'group' is applied to categorical data groups or ranks. thus, the literal logic of "many groups" underlies the statistical technique designed to analyze the relationship between multiple ordered categories.
Analysis
poly: from greek 'polys', meaning 'much, many'. a combining form indicating multiplicity. choric: derived from greek 'khoros', meaning 'chorus, dance, band of dancers or singers'. in modern scientific terminology, it relates to groups or aggregated data.