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psych (version 2.0.7)

Procedures for Psychological, Psychometric, and Personality Research

Description

A general purpose toolbox for personality, psychometric theory and experimental psychology. Functions are primarily for multivariate analysis and scale construction using factor analysis, principal component analysis, cluster analysis and reliability analysis, although others provide basic descriptive statistics. Item Response Theory is done using factor analysis of tetrachoric and polychoric correlations. Functions for analyzing data at multiple levels include within and between group statistics, including correlations and factor analysis. Functions for simulating and testing particular item and test structures are included. Several functions serve as a useful front end for structural equation modeling. Graphical displays of path diagrams, factor analysis and structural equation models are created using basic graphics. Some of the functions are written to support a book on psychometric theory as well as publications in personality research. For more information, see the web page.

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Install

install.packages('psych')

Monthly Downloads

150,960

Version

2.0.7

License

GPL (>= 2)

Maintainer

William Revelle

Last Published

July 26th, 2020

Functions in psych (2.0.7)

ICLUST.graph

create control code for ICLUST graphical output
iclust

iclust: Item Cluster Analysis -- Hierarchical cluster analysis using psychometric principles
Harman

Five data sets from Harman (1967). 9 cognitive variables from Holzinger and 8 emotional variables from Burt
00.psych

A package for personality, psychometric, and psychological research
Gleser

Example data from Gleser, Cronbach and Rajaratnam (1965) to show basic principles of generalizability theory.
ICC

Intraclass Correlations (ICC1, ICC2, ICC3 from Shrout and Fleiss)
AUC

Decision Theory measures of specificity, sensitivity, and d prime
ICLUST.cluster

Function to form hierarchical cluster analysis of items
Gorsuch

Example data set from Gorsuch (1997) for an example factor extension.
KMO

Find the Kaiser, Meyer, Olkin Measure of Sampling Adequacy
SD

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

Apply the Very Simple Structure, MAP, and other criteria to determine the appropriate number of factors.
Garcia

Data from the sexism (protest) study of Garcia, Schmitt, Branscome, and Ellemers (2010)
ICLUST.rgraph

Draw an ICLUST graph using the Rgraphviz package
bestScales

A bootstrap aggregation function for choosing most predictive unit weighted items
Promax

Perform Procustes,bifactor, promax or targeted rotations and return the inter factor angles.
bfi

25 Personality items representing 5 factors
Tucker

9 Cognitive variables discussed by Tucker and Lewis (1973)
Pinv

Compute the Moore-Penrose Pseudo Inverse of a matrix
bi.bars

Draw pairs of bargraphs based on two groups
bock

Bock and Liberman (1970) data set of 1000 observations of the LSAT
Schmid

12 variables created by Schmid and Leiman to show the Schmid-Leiman Transformation
VSS.parallel

Compare real and random VSS solutions
ICLUST.sort

Sort items by absolute size of cluster loadings
Bechtoldt

Seven data sets showing a bifactor solution.
VSS.plot

Plot VSS fits
biplot.psych

Draw biplots of factor or component scores by factor or component loadings
corCi

Bootstrapped and normal confidence intervals for raw and composite correlations
block.random

Create a block randomized structure for n independent variables
cattell

12 cognitive variables from Cattell (1963)
cor2dist

Convert correlations to distances (necessary to do multidimensional scaling of correlation data)
corFiml

Find a Full Information Maximum Likelihood (FIML) correlation or covariance matrix from a data matrix with missing data
cosinor

Functions for analysis of circadian or diurnal data
ellipses

Plot data and 1 and 2 sigma correlation ellipses
pairwiseCount

Count number of pairwise cases for a data set with missing (NA) data and impute values.
bassAckward

The Bass-Ackward factoring algorithm discussed by Goldberg
cluster.fit

cluster Fit: fit of the cluster model to a correlation matrix
anova.psych

Model comparison for regression, mediation, and factor analysis
error.bars

Plot means and confidence intervals
VSS.scree

Plot the successive eigen values for a scree test
Yule

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

Basic summary statistics by group
cor.plot

Create an image plot for a correlation or factor matrix
alpha

Find two estimates of reliability: Cronbach's alpha and Guttman's Lambda 6.
Dwyer

8 cognitive variables used by Dwyer for an example.
circ.tests

Apply four tests of circumplex versus simple structure
diagram

Helper functions for drawing path model diagrams
fa.diagram

Graph factor loading matrices
eigen.loadings

Convert eigen vectors and eigen values to the more normal (for psychologists) component loadings
comorbidity

Convert base rates of two diagnoses and their comorbidity into phi, Yule, and tetrachorics
fa.extension

Apply Dwyer's factor extension to find factor loadings for extended variables
cohen.d

Find Cohen d and confidence intervals
cluster.loadings

Find item by cluster correlations, corrected for overlap and reliability
fa.lookup

A set of functions for factorial and empirical scale construction
describe

Basic descriptive statistics useful for psychometrics
fa.poly

Deprecated Exploratory Factor analysis functions. Please use fa
scoreOverlap

Find correlations of composite variables (corrected for overlap) from a larger matrix.
correct.cor

Find dis-attenuated correlations given correlations and reliabilities
error.crosses

Plot x and y error bars
corr.test

Find the correlations, sample sizes, and probability values between elements of a matrix or data.frame.
fa.sort

Sort factor analysis or principal components analysis loadings
error.dots

Show a dot.chart with error bars for different groups or variables
factor.model

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

Various ways to estimate factor scores for the factor analysis model
factor.rotate

``Hand" rotate a factor loading matrix
fa.random

A first approximation to Random Effects Exploratory Factor Analysis
cluster.plot

Plot factor/cluster loadings and assign items to clusters by their highest loading.
cluster2keys

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

Two way plots of means, error bars, and sample sizes
error.bars.by

Plot means and confidence intervals for multiple groups
lowerUpper

Combine two square matrices to have a lower off diagonal for one, upper off diagonal for the other
fparse

Parse and exten formula input from a model and return the DV, IV, and associated terms.
fa

Exploratory Factor analysis using MinRes (minimum residual) as well as EFA by Principal Axis, Weighted Least Squares or Maximum Likelihood
fisherz

Transformations of r, d, and t including Fisher r to z and z to r and confidence intervals
fa.parallel

Scree plots of data or correlation matrix compared to random ``parallel" matrices
make.keys

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

R* = R- F F'
esem

Perform and Exploratory Structural Equation Model (ESEM) by using factor extension techniques
paired.r

Test the difference between (un)paired correlations
geometric.mean

Find the geometric mean of a vector or columns of a data.frame.
glb.algebraic

Find the greatest lower bound to reliability.
kaiser

Apply the Kaiser normalization when rotating factors
polychor.matrix

Phi or Yule coefficient matrix to polychoric coefficient matrix
irt.responses

Plot probability of multiple choice responses as a function of a latent trait
factor.stats

Find various goodness of fit statistics for factor analysis and principal components
p.rep

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

Find the interpolated sample median, quartiles, or specific quantiles for a vector, matrix, or data frame
irt.item.diff.rasch

Simple function to estimate item difficulties using IRT concepts
factor2cluster

Extract cluster definitions from factor loadings
irt.fa

Item Response Analysis by Exploratory Factor Analysis of tetrachoric/polychoric correlations
irt.1p

Item Response Theory estimate of theta (ability) using a Rasch (like) model
predict.psych

Prediction function for factor analysis, principal components (pca), bestScales
cor.wt

The sample size weighted correlation may be used in correlating aggregated data
cor.smooth

Smooth a non-positive definite correlation matrix to make it positive definite
cortest.bartlett

Bartlett's test that a correlation matrix is an identity matrix
omega.graph

Graph hierarchical factor structures
sim

Functions to simulate psychological/psychometric data.
sim.VSS

create VSS like data
phi.demo

A simple demonstration of the Pearson, phi, and polychoric corelation
outlier

Find and graph Mahalanobis squared distances to detect outliers
scaling.fits

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

Chi square tests of whether a single matrix is an identity matrix, or a pair of matrices are equal.
cohen.kappa

Find Cohen's kappa and weighted kappa coefficients for correlation of two raters
scoreIrt

Find Item Response Theory (IRT) based scores for dichotomous or polytomous items
phi2tetra

Convert a phi coefficient to a tetrachoric correlation
draw.tetra

Draw a correlation ellipse and two normal curves to demonstrate tetrachoric correlation
mssd

Find von Neuman's Mean Square of Successive Differences
logistic

Logistic transform from x to p and logit transform from p to x
scatterHist

Draw a scatter plot with associated X and Y histograms, densities and correlation
r.test

Tests of significance for correlations
multi.hist

Multiple histograms with density and normal fits on one page
smc

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

Correct correlations for restriction of range. (Thorndike Case 2)
scoreItems

Score item composite scales and find Cronbach's alpha, Guttman lambda 6 and item whole correlations
Spengler

Project Talent data set from Marion Spengler and Rodica Damian
headTail

Combine calls to head and tail
score.multiple.choice

Score multiple choice items and provide basic test statistics
sim.hierarchical

Create a population or sample correlation matrix, perhaps with hierarchical structure.
plot.psych

Plotting functions for the psych package of class ``psych"
sim.item

Generate simulated data structures for circumplex, spherical, or simple structure
dummy.code

Create dummy coded variables
polar

Convert Cartesian factor loadings into polar coordinates
cta

Simulate the C(ues) T(endency) A(ction) model of motivation
principal

Principal components analysis (PCA)
manhattan

"Manhattan" plots of correlations with a set of criteria.
sim.structure

Create correlation matrices or data matrices with a particular measurement and structural model
mat.sort

Sort the elements of a correlation matrix to reflect factor loadings
sim.multilevel

Simulate multilevel data with specified within group and between group correlations
iclust.diagram

Draw an ICLUST hierarchical cluster structure diagram
print.psych

Print and summary functions for the psych class
test.psych

Testing of functions in the psych package
testRetest

Find various test-retest statistics, including test, person and item reliability
test.irt

A simple demonstration (and test) of various IRT scoring algorthims.
Tal_Or

Data set testing causal direction in presumed media influence
densityBy

Create a 'violin plot' or density plot of the distribution of a set of variables
factor.congruence

Coefficient of factor congruence
scoreWtd

Score items using regression or correlation based weights
faCor

Correlations between two factor analysis solutions
splitHalf

Alternative estimates of test reliabiity
simulation.circ

Simulations of circumplex and simple structure
fa.multi

Multi level (hierarchical) factor analysis
factor.fit

How well does the factor model fit a correlation matrix. Part of the VSS package
psych.misc

Miscellaneous helper functions for the psych package
harmonic.mean

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

Calculate McDonald's omega estimates of general and total factor saturation
multilevel.reliability

Find and plot various reliability/gneralizability coefficients for multilevel data
mixedCor

Find correlations for mixtures of continuous, polytomous, and dichotomous variables
spider

Make "radar" or "spider" plots.
matrix.addition

A function to add two vectors or matrices
partial.r

Find the partial correlations for a set (x) of variables with set (y) removed.
mediate

Estimate and display direct and indirect effects of mediators and moderator in path models
mardia

Calculate univariate or multivariate (Mardia's test) skew and kurtosis for a vector, matrix, or data.frame
statsBy

Find statistics (including correlations) within and between groups for basic multilevel analyses
scrub

A utility for basic data cleaning and recoding. Changes values outside of minimum and maximum limits to NA.
reverse.code

Reverse the coding of selected items prior to scale analysis
sat.act

3 Measures of ability: SATV, SATQ, ACT
parcels

Find miniscales (parcels) of size 2 or 3 from a set of items
pairs.panels

SPLOM, histograms and correlations for a data matrix
table2matrix

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

Find the phi coefficient of correlation between two dichotomous variables
superMatrix

Form a super matrix from two sub matrices.
setCor

Multiple Regression and Set Correlation from matrix or raw input
winsor

Find the Winsorized scores, means, sds or variances for a vector, matrix, or data.frame
withinBetween

An example of the distinction between within group and between group correlations
thurstone

Thurstone Case V scaling
tetrachoric

Tetrachoric, polychoric, biserial and polyserial correlations from various types of input
residuals.psych

Extract residuals from various psych objects
rescale

Function to convert scores to ``conventional " metrics
score.alpha

Score scales and find Cronbach's alpha as well as associated statistics
sim.anova

Simulate a 3 way balanced ANOVA or linear model, with or without repeated measures.
schmid

Apply the Schmid Leiman transformation to a correlation matrix
sim.congeneric

Simulate a congeneric data set
unidim

Several indices of the unidimensionality of a set of variables.
structure.diagram

Draw a structural equation model specified by two measurement models and a structural model
structure.list

Create factor model matrices from an input list
tr

Find the trace of a square matrix