EKC | R Documentation |
The empirical Kaiser criterion incorporates random sampling variations of the
eigenvalues from the Kaiser-Guttman criterion (KGC
; see Auerswald & Moshagen
, 2019; Braeken & van Assen, 2017). The code is based on Auerswald and Moshagen
(2019).
EKC( x, N = NA, use = c("pairwise.complete.obs", "all.obs", "complete.obs", "everything", "na.or.complete"), cor_method = c("pearson", "spearman", "kendall") )
x |
data.frame or matrix. data.frame or matrix of raw data or matrix with correlations. |
N |
numeric. The number of observations. Only needed if x is a correlation matrix. |
use |
character. Passed to |
cor_method |
character. Passed to |
The Kaiser-Guttman criterion was defined with the intend that a factor
should only be extracted if it explains at least as much variance as a single
factor (see KGC
). However, this only applies to population-level
correlation matrices. Due to sampling variation, the KGC strongly overestimates
the number of factors to retrieve (e.g., Zwick & Velicer, 1986). To account
for this and to introduce a factor retention method that performs well with
small number of indicators and correlated factors (cases where the performance
of parallel analysis, see PARALLEL
, is known to deteriorate)
Braeken and van Assen (2017) introduced the empirical Kaiser criterion in
which a series of reference eigenvalues is created as a function of the
variables-to-sample-size ratio and the observed eigenvalues.
Braeken and van Assen (2017) showed that "(a) EKC performs about as well as parallel analysis for data arising from the null, 1-factor, or orthogonal factors model; and (b) clearly outperforms parallel analysis for the specific case of oblique factors, particularly whenever factor intercorrelation is moderate to high and the number of variables per factor is small, which is characteristic of many applications these days" (p.463-464).
The EKC
function can also be called together with other factor
retention criteria in the N_FACTORS
function.
A list of class EKC containing
eigenvalues |
A vector containing the eigenvalues found on the correlation matrix of the entered data. |
n_factors |
The number of factors to retain according to the empirical Kaiser criterion. |
references |
The reference eigenvalues. |
settings |
A list with the settings used. |
Auerswald, M., & Moshagen, M. (2019). How to determine the number of factors to retain in exploratory factor analysis: A comparison of extraction methods under realistic conditions. Psychological Methods, 24(4), 468–491. https://doi.org/10.1037/met0000200
Braeken, J., & van Assen, M. A. (2017). An empirical Kaiser criterion. Psychological Methods, 22, 450 – 466. http://dx.doi.org/10.1037/ met0000074
Zwick, W. R., & Velicer, W. F. (1986). Comparison of five rules for determining the number of components to retain. Psychological Bulletin, 99, 432–442. http://dx.doi.org/10.1037/0033-2909.99.3.432
Other factor retention criteria: CD
,
HULL
, KGC
, PARALLEL
,
SMT
N_FACTORS
as a wrapper function for this and all
the above-mentioned factor retention criteria.
EKC(test_models$baseline$cormat, N = 500)
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