Find dis-attenuated correlations and give alpha reliabilities
Fisher z transform of r
How well does the factor model fit a correlation matrix. Part of the VSS package
Principal components analysis
Generate simulated data structures for circumplex or simple structure
Calculate the omega estimate of factor saturation
Count number of pairwise cases for a data set with missing (NA) data.
create VSS like data
sort items by absolute size of cluster loadins
Function to form hierarchical cluster analysis of items
Basic summary statistics by group
Find R = F F' + U2 is the basic factor model
Actually, what does this do? Convert a matrix of phi coefficients to a matrix of polycoric correlations
Simulations of circumplex and simple structure
Multiple histograms on one screen
Find correlations of composite variables from a larger matrix
Plot a scree test
Compare real and random VSS solutions
Plot VSS fits
ICLUST: Item Cluster Analysis -- Hierarchical cluster analysis using psychometric principals
Create demo data for psychometrics
Item Response Theory estimate of theta (ability) using a Rasch (like) model
Apply the Schmid Leiman transformation to a correlation matrix
Score item composite scales and find Cronbach's alpha as well as associated statistics
Apply the Very Simple Structure criterion to determine the appropriate number of factors.
SPLOM, histograms and correlations for a data matrix
cluster Fit: fit of the cluster model to a correlation matrix
Score scales and find Cronbach's alpha as well as associated statistics
Simple function to estimate item difficulties using IRT concepts
Coefficient of factor congruence
A package for personality, psychometric, and psychological research
Find the phi coefficient of correlation between two dichotomous variables
Cronbach alpha for a scale
A function to add two vectors or matrices
Apply four tests of circumplex versus simple structure
create control code for ICLUST graphical output
Extract eigen vectors, eigen values, show loadings
R* = R- F F'
Basic descriptive statistics useful for psychometrics
shortcut for reading from the clipboard
Multiple Regression from matrix input
Principal Axis Factor Analysis
Find the geometric mean of a vector or columns of a data.frame.
Test the difference between paired correlations
"Hand" rotate a factor loading matrix
Create a population or sample correlation matrix with hierachical structure.
Find item by cluster correlations, corrected for overlap and reliability
Convert a phi coefficient to a polychoric correlation
Extract cluster definitions from factor loadings
Calculate skew for a vector, matrix, or data.frame
Plot x and y error bars
Find the harmonic mean of a vector, matrix, or columns of a data.frame