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psych (version 1.8.4)

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

201,650

Version

1.8.4

License

GPL (>= 2)

Maintainer

William Revelle

Last Published

May 6th, 2018

Functions in psych (1.8.4)

Tucker

9 Cognitive variables discussed by Tucker and Lewis (1973)
VSS.plot

Plot VSS fits
bestScales

A bootstrap aggregation (bagging) function for choosing most predictive items
ability

16 ability items scored as correct or incorrect.
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.
cor.smooth

Smooth a non-positive definite correlation matrix to make it positive definite
cattell

12 cognitive variables from Cattell (1963)
bock

Bock and Liberman (1970) data set of 1000 observations of the LSAT
circ.tests

Apply four tests of circumplex versus simple structure
cor.ci

Bootstrapped confidence intervals for raw and composite correlations
cor.wt

The sample size weighted correlation may be used in correlating aggregated data
cities

Distances between 11 US cities
VSS.scree

Plot the successive eigen values for a scree test
burt

11 emotional variables from Burt (1915)
bfi

25 Personality items representing 5 factors
corr.test

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

Find dis-attenuated correlations given correlations and reliabilities
scoreOverlap

Find correlations of composite variables (corrected for overlap) from a larger matrix.
bi.bars

Draw pairs of bargraphs based on two groups
cor.plot

Create an image plot for a correlation or factor matrix
cluster.loadings

Find item by cluster correlations, corrected for overlap and reliability
biplot.psych

Draw biplots of factor or component scores by factor or component loadings
cluster.fit

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

Galton's example of the relationship between height and 'cubit' or forearm length
draw.tetra

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

Two data sets of affect and arousal scores as a function of personality and movie conditions
count.pairwise

Count number of pairwise cases for a data set with missing (NA) data.
Bechtoldt

Seven data sets showing a bifactor solution.
blant

A 29 x 29 matrix that produces weird factor analytic results
cosinor

Functions for analysis of circadian or diurnal data
cta

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

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

Create dummy coded variables
epi.bfi

13 personality scales from the Eysenck Personality Inventory and Big 5 inventory
describeBy

Basic summary statistics by group
df2latex

Convert a data frame, correlation matrix, or factor analysis output to a LaTeX table
error.bars

Plot means and confidence intervals
dfOrder

Sort (order) a dataframe or matrix by multiple columns
fa.lookup

A set of functions for factorial and empirical scale construction
block.random

Create a block randomized structure for n independent variables
blot

Bond's Logical Operations Test -- BLOT
eigen.loadings

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

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

8 cognitive variables used by Dwyer for an example.
diagram

Helper functions for drawing path model diagrams
fa.parallel

Scree plots of data or correlation matrix compared to random ``parallel" matrices
fa.multi

Multi level (hierarchical) factor analysis
factor.scores

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

Coefficient of factor congruence
factor.fit

How well does the factor model fit a correlation matrix. Part of the VSS package
error.bars.by

Plot means and confidence intervals for multiple groups
errorCircles

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

Find various goodness of fit statistics for factor analysis and principal components
interp.median

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

A first approximation to Random Effects Exploratory Factor Analysis
factor.model

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

Find Cohen d and confidence intervals
fa.sort

Sort factor analysis or principal components analysis loadings
iqitems

16 multiple choice IQ items
cortest.bartlett

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

Convert base rates of two diagnoses and their comorbidity into phi, Yule, and tetrachorics
income

US family income from US census 2008
iclust.diagram

Draw an ICLUST hierarchical cluster structure diagram
logistic

Logistic transform from x to p and logit transform from p to x
make.keys

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

Galton's Mid parent child height data
cortest.mat

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

Transformations of r, d, and t including Fisher r to z and z to r and confidence intervals
mat.sort

Sort the elements of a correlation matrix to reflect factor loadings
lowerUpper

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

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

Find miniscales (parcels) of size 2 or 3 from a set of items
neo

NEO correlation matrix from the NEO_PI_R manual
msq

75 mood items from the Motivational State Questionnaire for 3896 participants
paired.r

Test the difference between (un)paired correlations
msqR

75 mood items from the Motivational State Questionnaire for 3032 unique participants
cluster2keys

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

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

Plotting functions for the psych package of class ``psych"
ellipses

Plot data and 1 and 2 sigma correlation ellipses
r.test

Tests of significance for correlations
polar

Convert Cartesian factor loadings into polar coordinates
rangeCorrection

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

Deprecated Exploratory Factor analysis functions. Please use fa
describe

Basic descriptive statistics useful for psychometrics
pairs.panels

SPLOM, histograms and correlations for a data matrix
geometric.mean

Find the geometric mean of a vector or columns of a data.frame.
cor2dist

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

State Anxiety data from the PMC lab over multiple occasions.
corFiml

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

Find the greatest lower bound to reliability.
kaiser

Apply the Kaiser normalization when rotating factors
residuals.psych

Extract residuals from various psych objects
epi

Eysenck Personality Inventory (EPI) data for 3570 participants
reverse.code

Reverse the coding of selected items prior to scale analysis
cushny

A data set from Cushny and Peebles (1905) on the effect of three drugs on hours of sleep, used by Student (1908)
cohen.kappa

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

Set Correlation and Multiple Regression from matrix or raw input
matrix.addition

A function to add two vectors or matrices
fa.diagram

Graph factor loading matrices
sat.act

3 Measures of ability: SATV, SATQ, ACT
densityBy

Create a 'violin plot' or density plot of the distribution of a set of variables
error.crosses

Plot x and y error bars
factor.residuals

R* = R- F F'
fa.extension

Apply Dwyer's factor extension to find factor loadings for extended variables
sim

Functions to simulate psychological/psychometric data.
scoreIrt

Find Item Response Theory (IRT) based scores for dichotomous or polytomous items
factor.rotate

``Hand" rotate a factor loading matrix
mediate

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

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

Alternative estimates of test reliabiity
harmonic.mean

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

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

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

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

A sample from the SAPA Personality Inventory including an item dictionary and scoring keys.
irt.item.diff.rasch

Simple function to estimate item difficulties using IRT concepts
omega.graph

Graph hierarchical factor structures
mssd

Find von Neuman's Mean Square of Successive Differences
omega

Calculate McDonald's omega estimates of general and total factor saturation
spider

Make "radar" or "spider" plots.
irt.fa

Item Response Analysis by Exploratory Factor Analysis of tetrachoric/polychoric correlations
multi.hist

Multiple histograms with density and normal fits on one page
phi.demo

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

Find various test-retest statistics, including test, person and item reliability
phi2tetra

Convert a phi coefficient to a tetrachoric correlation
table2matrix

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

Find and graph Mahalanobis squared distances to detect outliers
esem

Perform and Exploratory Structural Equation Model (ESEM) by using factor extension techniques
p.rep

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

Phi or Yule coefficient matrix to polychoric coefficient matrix
schmid

Apply the Schmid Leiman transformation to a correlation matrix
score.alpha

Score scales and find Cronbach's alpha as well as associated statistics
tetrachoric

Tetrachoric, polychoric, biserial and polyserial correlations from various types of input
unidim

Several indices of the unidimensionality of a set of variables.
scaling.fits

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

Score multiple choice items and provide basic test statistics
predict.psych

Prediction function for factor analysis or principal components
scrub

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

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

Paired comparison of preferences for 9 vegetables
factor2cluster

Extract cluster definitions from factor loadings
Utility

Useful utility functions for file/directory exploration and manipulation.
statsBy

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

Combine calls to head and tail
heights

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

Data set testing causal direction in presumed media influence
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
irt.responses

Plot probability of multiple choice responses as a function of a latent trait
irt.1p

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

Form a super matrix from two sub matrices.
peas

Galton`s Peas
mixedCor

Find correlations for mixtures of continuous, polytomous, and dichotomous variables
psych.misc

Miscellaneous helper functions for the psych package
scatterHist

Draw a scatter plot with associated X and Y histograms, densities and correlation
winsor

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

Simulate a congeneric data set
withinBetween

An example of the distinction between within group and between group correlations
sim.item

Generate simulated data structures for circumplex, spherical, or simple structure
sim.multilevel

Simulate multilevel data with specified within group and between group correlations
sim.hierarchical

Create a population or sample correlation matrix, perhaps with hierarchical structure.
test.irt

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

Find the phi coefficient of correlation between two dichotomous variables
test.psych

Testing of functions in the psych package
principal

Principal components analysis (PCA)
print.psych

Print and summary functions for the psych class
read.file

Shortcuts for reading from the clipboard or a file
rescale

Function to convert scores to ``conventional " metrics
sim.anova

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

create VSS like data
sim.structure

Create correlation matrices or data matrices with a particular measurement and structural model
simulation.circ

Simulations of circumplex and simple structure
tr

Find the trace of a square matrix
thurstone

Thurstone Case V scaling
Harman

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

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

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

create control code for ICLUST graphical output
ICC

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

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

Function to form hierarchical cluster analysis of items
00.psych

A package for personality, psychometric, and psychological research
Garcia

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

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

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

The Schutz correlation matrix example from Shapiro and ten Berge
Schmid

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

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

Compare real and random VSS solutions
ICLUST.rgraph

Draw an ICLUST graph using the Rgraphviz package
iclust

iclust: Item Cluster Analysis -- Hierarchical cluster analysis using psychometric principles
ICLUST.sort

Sort items by absolute size of cluster loadings
Promax

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