qflag: Q methodology: automatic flagging of Q-sorts

Description

Applies the two standard algorithms to pre-flag Q-sorts automatically, for posterior calculation of the statement scores.

Usage

qflag(loa, nstat)

Arguments

loa

a Q-sort factor loading matrix obtained, for example from unclass(principal(...)$loadings), or from qmethod(...)$loa.

nstat

number of statements in the study.

Details

These are the two standard criteria for automatic flagging used in Q method analysis:

Q-sorts which factor loading is higher than the threshold for p-value < 0.05, and
Q-sorts which square loading is higher than the sum of square loadings of the same Q-sort in all other factors.

Returns a logical matrix with Q-sorts as rows, and factors as columns.

References

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

Van Exel, J., de Graaf, G., Rietveld, P., 2011. "'I can do perfectly well without a car!'" Transportation 38, 383-407 (Page 388, footnote 8).

See further references on the methodology in qmethod-package.

Examples

Run this code

# NOT RUN {
data(lipset)
library(psych)
loa <- as.data.frame(unclass(principal(lipset[[1]], nfactors = 3, 
                                       rotate = "varimax")$loadings))
flagged <- qflag(loa = loa, nstat = nrow(lipset[[1]]))
summary(flagged)
# }

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