%+%                     A function to add two vectors or matrices
ICLUST                  ICLUST: Item Cluster Analysis -- Hierarchical
                        cluster analysis using psychometric principles
ICLUST.cluster          Function to form hierarchical cluster analysis
                        of items
ICLUST.graph            create control code for ICLUST graphical output
ICLUST.rgraph           Draw an ICLUST graph using the Rgraphviz
                        package
ICLUST.sort             Sort items by absolute size of cluster loadings
VSS                     Apply the Very Simple Structure criterion to
                        determine the appropriate number of factors.
VSS.parallel            Compare real and random VSS solutions
VSS.plot                Plot VSS fits
VSS.scree               Plot a scree test
VSS.simulate            create VSS like data
alpha.scale             Cronbach alpha for a scale
bfi                     25 Personality items representing 5 factors
circ.simulation         Simulations of circumplex and simple structure
circ.tests              Apply four tests of circumplex versus simple
                        structure
cluster.cor             Find correlations of composite variables from a
                        larger matrix
cluster.fit             cluster Fit: fit of the cluster model to a
                        correlation matrix
cluster.loadings        Find item by cluster correlations, corrected
                        for overlap and reliability
cluster.plot            Plot factor/cluster loadings and assign items
                        to clusters by their highest loading
congeneric.sim          Simulate a congeneric data set
correct.cor             Find dis-attenuated correlations and give alpha
                        reliabilities
count.pairwise          Count number of pairwise cases for a data set
                        with missing (NA) data.
describe                Basic descriptive statistics useful for
                        psychometrics
describe.by             Basic summary statistics by group
eigen.loadings          Convert eigen vectors and eigen values to the
                        more normal (for psychologists) component
                        loadings
error.bars              Plot means and confidence intervals
error.crosses           Plot x and y error bars
fa.graph                Graph factor loading matrices
fa.parallel             Scree plots of data or correlation matrix
                        compared to random "parallel" matrices
factor.congruence       Coefficient of factor congruence
factor.fit              How well does the factor model fit a
                        correlation matrix. Part of the VSS package
factor.model            Find R = F F' + U2 is the basic factor model
factor.pa               Principal Axis Factor Analysis
factor.residuals        R* = R- F F'
factor.rotate           "Hand" rotate a factor loading matrix
factor2cluster          Extract cluster definitions from factor
                        loadings
fisherz                 Fisher z transform of r
geometric.mean          Find the geometric mean of a vector or columns
                        of a data.frame.
harmonic.mean           Find the harmonic mean of a vector, matrix, or
                        columns of a data.frame
iqitems                 14 multiple choice IQ items
irt.1p                  Item Response Theory estimate of theta
                        (ability) using a Rasch (like) model
irt.item.diff.rasch     Simple function to estimate item difficulties
                        using IRT concepts
item.sim                Generate simulated data structures for
                        circumplex or simple structure
kurtosi                 Kurtosis of a vector, matrix, or data frame
make.hierarchical       Create a population or sample correlation
                        matrix with hierachical structure.
mat.regress             Multiple Regression from matrix input
multi.hist              Multiple histograms on one screen
omega                   Calculate the omega estimate of factor
                        saturation
omega.graph             Graph hierarchical factor structures
p.rep                   Find the probability of replication for an F,
                        t, or r and estimate effect size
paired.r                Test the difference between paired correlations
pairs.panels            SPLOM, histograms and correlations for a data
                        matrix
phi                     Find the phi coefficient of correlation between
                        two dichotomous variables
phi2poly                Convert a phi coefficient to a polychoric
                        correlation
polar                   polar :convert Cartesian factor loadings into
                        polar coordinates
poly.mat                Find polychoric correlations of item data
polychor.matrix         Actually, what does this do? Convert a matrix
                        of phi coefficients to a matrix of polycoric
                        correlations
principal               Principal components analysis
psych-package           A package for personality, psychometric, and
                        psychological research
psycho.demo             Create demo data for psychometrics
read.clipboard          shortcut for reading from the clipboard
sat.act                 3 Measures of ability: SATV, SATQ, ACT
schmid                  Apply the Schmid Leiman transformation to a
                        correlation matrix
score.alpha             Score scales and find Cronbach's alpha as well
                        as associated statistics
score.items             Score item composite scales and find Cronbach's
                        alpha as well as associated statistics
score.multiple.choice   Score multiple choice items and provide basic
                        test statistics
skew                    Calculate skew for a vector, matrix, or
                        data.frame
test.psych              Testing of functions in the psych package
