qmethod (version 1.0)

qfcharact: Q methodology: factor characteristics

Description

Calculates the general factor characteristics: number of flagged Q-sorts, composite reliability, standard errors of factor scores, and comparisons between factors.

Usage

qfcharact(loa, flagged, nqsorts, zsc, nfactors, floa, av_rel_coef=0.800)

Arguments

loa

a matrix or a data frame containing raw data, with statements as rows, Q-sorts as columns, and the scores of the columns in the distribution in each cell.

nfactors

number of factors to extract using PCA.

flagged

a data frame of type logical, indicating which Q-sorts are flagged for each factor. Provided manually or automatically using qflag.

nqsorts

number of Q-sorts in the study.

zsc

a data frame with the z-scores for statements, calculated using qzscores.

floa

a data frame with the factor loadings, calculated using PCA or Centroid factor analysis.

av_rel_coef

average reliability coefficient (the individual variability of a respondent), estimated by default as 0.8.

Details

The default qmethod does automatic flagging and uses varimax rotation. The latter can be replaced by other methods for rotation allowed in principal.

If input data contains row names and variable names, these will be kept throughout the analysis. Input data is validated, and it will give an error either if there are non numerical values or if the number of statements and Q sorts introduced does not match with the input data.

This function works with any number of factors rotated, of statements, and of Q-sorts. The function returns the following factor characteristics:

1. Average reliability coefficient.

Number of loading Q-sorts. Eigenvalues. Percentage of explained variance. Composite reliability. Standard error of factor scores. Correlation coefficients between factors z-scores. Standard errors of differences.

References

Brown, S. R., 1980 Political subjectivity: Applications of Q methodology in political science, New Haven, CT: Yale University Press.

See further references on the methodology in qmethod-package.