Sentence examples for matrix of polychoric from inspiring English sources
Therefore, we proceeded to estimate the models from the matrix of polychoric correlations [ 38].
The analysis was performed on the matrix of polychoric correlations, reflecting the ordinal nature of the input data.
WLSMV is one of the estimators that are robust to non-normality and involves the analysis of a matrix of polychoric correlations.
Data from these participants were used to estimate a matrix of polychoric correlations between all 89 symptom variables that was used in all factor analyses.
In this case, the EFA and CFA should be based on the matrix of polychoric correlations (rather than Pearson), which is also robust to underlying non-normality.
IRT and factor analysis are isomorphic when the factor analysis is performed on a matrix of polychoric correlations and only one latent variable is modeled [ 26- 28].
An omnibus test of the equality of the matrices of polychoric correlations and of the threshold structure of the items across gender was also carried out, separately, for the pooled sample and for each age group.
Data were examined through multi-group confirmatory factor analyses (CFA) executed with Mplus-Version 4. Given the highly skewed distribution of the K6 items and their ordinal nature, CFAs were carried out from matrices of polychoric correlations and a robust mean adjusted weighted least squares estimator (WLSMV) as recommended by Brown [ 49], Flora and Curran [ 57] and Muthén and Muthén [ 51].
On the other hand, the use of polychoric correlation matrixes for the estimation of the factor analysis models resulted efficient and made it possible to incorporate both the weightings of the sample subjects and the ordinal metric of the items.
To examine the unidimensionality of the item pool, we tested confirmatory, single and bifactor models with factor analysis methods suitable for ordinal data, namely analysis of polychoric correlation matrices using a diagonally weighted least squares estimator [ 4, 37, 38].
Thus, a polychoric correlation matrix of BDI-II items was estimated.
