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psych (version 1.0-51)

Procedures for Personality and Psychological Research

Description

A number of routines for personality, psychometrics and experimental psychology. Functions are primarily for scale construction using factor analysis, cluster analysis and reliability analysis, although others provide basic descriptive statistics. For more information, see the personality-project.org/r.

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Install

install.packages('psych')

Monthly Downloads

242,751

Version

1.0-51

License

GPL version 2 or newer

Maintainer

William Revelle

Last Published

March 21st, 2025

Functions in psych (1.0-51)

bfi

25 Personality items representing 5 factors
kurtosi

Kurtosis of a vector, matrix, or data frame
bartlett.cortest

Bartlett's test that a correlation matrix is an identity matrix
smc

Find the Squared Multiple Correlation (SMC) of each variable with the remaining variables in a matrix
cluster.fit

cluster Fit: fit of the cluster model to a correlation matrix
factor2cluster

Extract cluster definitions from factor loadings
ICLUST.sort

Sort items by absolute size of cluster loadings
VSS.plot

Plot VSS fits
ICC

Intraclass Correlations (ICC1, ICC2, ICC3 from Shrout and Fleiss)
VSS.parallel

Compare real and random VSS solutions
Yule

From a two by two table, find the Yule coefficients of association, convert to phi, or polychoric, recreate table the table to create the Yule coefficient.
VSS.sim

create VSS like data
congeneric.sim

Simulate a congeneric data set
factor.rotate

``Hand" rotate a factor loading matrix
ICLUST

ICLUST: Item Cluster Analysis -- Hierarchical cluster analysis using psychometric principles
wkappa

Find Cohen's kappa and weighted kappa coefficients for correlation of two raters
factor.congruence

Coefficient of factor congruence
alpha.scale

Cronbach alpha for a scale
eigen.loadings

Convert eigen vectors and eigen values to the more normal (for psychologists) component loadings
ICLUST.graph

create control code for ICLUST graphical output
fa.graph

Graph factor loading matrices
interp.median

Find the interpolated sample median, quartiles, or specific quantiles for a vector, matrix, or data frame
error.bars

Plot means and confidence intervals
circ.simulation

Simulations of circumplex and simple structure
ICLUST.rgraph

Draw an ICLUST graph using the Rgraphviz package
cluster.cor

Find correlations of composite variables from a larger matrix
SD

Find the Standard deviation for a vector, matrix, or data.frame - do not return error if there are no cases
heights

A data.frame of the Galton (1888) height and cubit data set.
factor.pa

Principal Axis Factor Analysis
factor.model

Find R = F F' + U2 is the basic factor model
fisherz

Fisher r to z and z to r and confidence intervals
error.crosses

Plot x and y error bars
error.bars.by

Plot means and confidence intervals for multiple groups
describe

Basic descriptive statistics useful for psychometrics
omega.graph

Graph hierarchical factor structures
count.pairwise

Count number of pairwise cases for a data set with missing (NA) data.
irt.item.diff.rasch

Simple function to estimate item difficulties using IRT concepts
galton

Galton's Mid parent child height data
cities

Distances between 11 US cities
item.sim

Generate simulated data structures for circumplex or simple structure
irt.1p

Item Response Theory estimate of theta (ability) using a Rasch (like) model
comorbidity

Convert base rates of two diagnoses and their comorbidity into phi, Yule, and tetrachorics
correct.cor

Find dis-attenuated correlations and give alpha reliabilities
mat.cortest

Chi square test of whether a single matrix is an identity matrix, or a pair of matrices are equal.
psych

A package for personality, psychometric, and psychological research
epi.bfi

13 personality scales from the Eysenck Personality Inventory and Big 5 inventory
ICLUST.cluster

Function to form hierarchical cluster analysis of items
VSS.scree

Plot a scree test
cluster.loadings

Find item by cluster correlations, corrected for overlap and reliability
factor.residuals

R* = R- F F'
cluster2keys

Convert a cluster vector (from e.g., kmeans) to a keys matrix suitable for scoring item clusters.
make.hierarchical

Create a population or sample correlation matrix, perhaps with hierarchical structure.
circ.tests

Apply four tests of circumplex versus simple structure
ellipses

Plot data and 1 and 2 sigma correlation ellipses
p.rep

Find the probability of replication for an F, t, or r and estimate effect size
cluster.plot

Plot factor/cluster loadings and assign items to clusters by their highest loading.
fa.parallel

Scree plots of data or correlation matrix compared to random ``parallel" matrices
poly.mat

Find polychoric correlations of item data
factor.fit

How well does the factor model fit a correlation matrix. Part of the VSS package
make.keys

Create a keys matrix for use by score.items or cluster.cor
describe.by

Basic summary statistics by group
geometric.mean

Find the geometric mean of a vector or columns of a data.frame.
scaling.fits

Test the adequacy of simple choice, logistic, or Thurstonian scaling.
VSS

Apply the Very Simple Structure and MAP criteria to determine the appropriate number of factors.
headtail

Combine calls to head and tail
table2matrix

Convert a table with counts to a matrix or data.frame representing those counts.
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
vegetables

Paired comparison of preferences for 9 vegetables
phi.demo

Create demo data for psychometrics
r.test

Tests of significance for correlations
tr

Find the trace of a square matrix
pairs.panels

SPLOM, histograms and correlations for a data matrix
mat.regress

Multiple Regression from matrix input
omega

Calculate the omega estimate of factor saturation
cubits

Galton's example of the relationship between height and 'cubit' or forearm length
phi2poly

Convert a phi coefficient to a polychoric correlation
test.psych

Testing of functions in the psych package
score.alpha

Score scales and find Cronbach's alpha as well as associated statistics
sat.act

3 Measures of ability: SATV, SATQ, ACT
matrix.addition

A function to add two vectors or matrices
thurstone

Thurstone Case V scaling
skew

Calculate skew for a vector, matrix, or data.frame
peas

Galton`s Peas
polar

Convert Cartesian factor loadings into polar coordinates
schmid

Apply the Schmid Leiman transformation to a correlation matrix
polychor.matrix

Phi or Yule coefficient matrix to polychoric coefficient matrix
read.clipboard

shortcut for reading from the clipboard
principal

Principal components analysis
rescale

Function to convert scores to ``conventional " metrics
phi

Find the phi coefficient of correlation between two dichotomous variables
winsor

Find the Winsorized scores or means for a vector, matrix, or data.frame
harmonic.mean

Find the harmonic mean of a vector, matrix, or columns of a data.frame
iqitems

14 multiple choice IQ items
paired.r

Test the difference between (un)paired correlations
multi.hist

Multiple histograms with density and normal fits on one page