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psych (version 1.5.8)

Procedures for Psychological, Psychometric, and Personality Research

Description

A general purpose toolbox for personality, psychometrics 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 multi-levels include within and between group statistics, including correlations and factor analysis. Functions for simulating 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 psychometrics as well as publications in personality research. For more information, see the personality-project.org/r webpage.

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Install

install.packages('psych')

Monthly Downloads

171,853

Version

1.5.8

License

GPL (>= 2)

Maintainer

William Revelle

Last Published

August 30th, 2015

Functions in psych (1.5.8)

scoreOverlap

Find correlations of composite variables (corrected for overlap) from a larger matrix.
Harman.political

Eight political variables used by Harman (1967) as example 8.17
cortest.mat

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

Plot means and confidence intervals for multiple groups
Harman.5

5 socio-economic variables from Harman (1967)
correct.cor

Find dis-attenuated correlations given correlations and reliabilities
Harman

Two data sets from Harman (1967). 9 cognitive variables from Holzinger and 8 emotional variables from Burt
epi.bfi

13 personality scales from the Eysenck Personality Inventory and Big 5 inventory
Harman.8

Correlations of eight physical variables (from Harman, 1966)
ICLUST.graph

create control code for ICLUST graphical output
mat.sort

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

Form a super matrix from two sub matrices.
KMO

Find the Kaiser, Meyer, Olkin Measure of Sampling Adequacy
cor.ci

Bootstrapped confidence intervals for raw and composite correlations
error.bars

Plot means and confidence intervals
VSS.plot

Plot VSS fits
Dwyer

8 cognitive variables used by Dwyer for an example.
heights

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

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

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

A set of functions for factorial and empirical scale construction
msq

75 mood items from the Motivational State Questionnaire for 3896 participants
circ.tests

Apply four tests of circumplex versus simple structure
sim.congeneric

Simulate a congeneric data set
Promax

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

25 Personality items representing 5 factors
cor.plot

Create an image plot for a correlation or factor matrix
ICLUST.sort

Sort items by absolute size of cluster loadings
factor.scores

Various ways to estimate factor scores for the factor analysis model
fa.parallel

Scree plots of data or correlation matrix compared to random ``parallel" matrices
corr.test

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

Convert base rates of two diagnoses and their comorbidity into phi, Yule, and tetrachorics
ICLUST.rgraph

Draw an ICLUST graph using the Rgraphviz package
Gorsuch

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

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

iclust: Item Cluster Analysis -- Hierarchical cluster analysis using psychometric principles
VSS.parallel

Compare real and random VSS solutions
Gleser

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

Graph factor loading matrices
cluster.plot

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

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

Seven data sets showing a bifactor solution.
corFiml

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

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

Find Cohen's kappa and weighted kappa coefficients for correlation of two raters
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.
print.psych

Print and summary functions for the psych class
cta

Simulate the C(ues) T(endency) A(ction) model of motivation
irt.fa

Item Response Analysis by Exploratory Factor Analysis of tetrachoric/polychoric correlations
burt

11 emotional variables from Burt (1915)
ICC

Intraclass Correlations (ICC1, ICC2, ICC3 from Shrout and Fleiss)
bi.bars

Draw pairs of bargraphs based on two groups
ability

16 ability items scored as correct or incorrect.
cities

Distances between 11 US cities
eigen.loadings

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

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

Helper functions for drawing path model diagrams
cosinor

Functions for analysis of circadian or diurnal data
scoreItems

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

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

Galton's example of the relationship between height and 'cubit' or forearm length
cor2dist

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

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

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

Paired comparison of preferences for 9 vegetables
parcels

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

Galton's Mid parent child height data
error.crosses

Plot x and y error bars
rescale

Function to convert scores to ``conventional " metrics
splitHalf

Alternative estimates of test reliabiity
mssd

Find von Neuman's Mean Square of Successive Differences
headTail

Combine calls to head and tail
omega.graph

Graph hierarchical factor structures
harmonic.mean

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

Coefficient of factor congruence
scatter.hist

Draw a scatter plot with associated X and Y histograms, densitie and correlation
matrix.addition

A function to add two vectors or matrices
phi2tetra

Convert a phi coefficient to a tetrachoric correlation
glb.algebraic

Find the greatest lower bound to reliability.
block.random

Create a block randomized structure for n independent variables
iqitems

16 multiple choice IQ items
errorCircles

Two way plots of means, error bars, and sample sizes
df2latex

Convert a data frame, correlation matrix, or factor analysis output to a LaTeX table
p.rep

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

Create factor model matrices from an input list
VSS.scree

Plot the successive eigen values for a scree test
kaiser

Apply the Kaiser normalization when rotating factors
factor2cluster

Extract cluster definitions from factor loadings
psych.misc

Miscellaneous helper functions for the psych package
sat.act

3 Measures of ability: SATV, SATQ, ACT
VSS

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

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

Function to form hierarchical cluster analysis of items
table2matrix

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

Plot data and 1 and 2 sigma correlation ellipses
mixed.cor

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

Create a 'violin plot' or density plot of the distribution of a set of variables
describe

Basic descriptive statistics useful for psychometrics
epi

Eysenck Personality Inventory (EPI) data for 3570 participants
00.psych

A package for personality, psychometric, and psychological research
factor.stats

Find various goodness of fit statistics for factor analysis and principal components
biplot.psych

Draw biplots of factor or component scores by factor or component loadings
predict.psych

Prediction function for factor analysis or principal components
fisherz

Fisher r to z and z to r and confidence intervals
structure.diagram

Draw a structural equation model specified by two measurement models and a structural model
score.multiple.choice

Score multiple choice items and provide basic test statistics
factor.fit

How well does the factor model fit a correlation matrix. Part of the VSS package
r.test

Tests of significance for correlations
fa.sort

Sort factor analysis or principal components analysis loadings
phi.demo

A simple demonstration of the Pearson, phi, and polychoric corelation
count.pairwise

Count number of pairwise cases for a data set with missing (NA) data.
irt.1p

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

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

Galton`s Peas
factor.residuals

R* = R- F F'
withinBetween

An example of the distinction between within group and between group correlations
multi.hist

Multiple histograms with density and normal fits on one page
plot.psych

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

Convert Cartesian factor loadings into polar coordinates
omega

Calculate McDonald's omega estimates of general and total factor saturation
score.alpha

Score scales and find Cronbach's alpha as well as associated statistics
residuals.psych

Extract residuals from various psych objects
cushny

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

create VSS like data
tetrachoric

Tetrachoric, polychoric, biserial and polyserial correlations from various types of input
draw.tetra

Draw a correlation ellipse and two normal curves to demonstrate tetrachoric correlation
paired.r

Test the difference between (un)paired correlations
phi

Find the phi coefficient of correlation between two dichotomous variables
describeBy

Basic summary statistics by group
partial.r

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

Phi or Yule coefficient matrix to polychoric coefficient matrix
tr

Find the trace of a square matrix
scrub

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

Simulations of circumplex and simple structure
cluster2keys

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

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

NEO correlation matrix from the NEO_PI_R manual
sim.item

Generate simulated data structures for circumplex, spherical, or simple structure
affect

Two data sets of affect and arousal scores as a function of personality and movie conditions
blot

Bond's Logical Operations Test -- BLOT
cor.smooth

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

9 Cognitive variables discussed by Tucker and Lewis (1973)
sim.structure

Create correlation matrices or data matrices with a particular measurement and structural model
read.clipboard

shortcut for reading from the clipboard
outlier

Find and graph Mahalanobis squared distances to detect outliers
setCor

Set Correlation and Multiple Regression from matrix or raw input
reverse.code

Reverse the coding of selected items prior to scale analysis
principal

Principal components analysis (PCA)
irt.item.diff.rasch

Simple function to estimate item difficulties using IRT concepts
test.psych

Testing of functions in the psych package
thurstone

Thurstone Case V scaling
cluster.fit

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

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

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

Functions to simulate psychological/psychometric data.
winsor

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

``Hand" rotate a factor loading matrix
interp.median

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

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

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

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

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

Find statistics (including correlations) within and between groups for basic multilevel analyses
dummy.code

Create dummy coded variables
income

US family income from US census 2008
iclust.diagram

Draw an ICLUST hierarchical cluster structure diagram
irt.responses

Plot probability of multiple choice responses as a function of a latent trait
mediate

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

Make "radar" or "spider" plots.
sim.multilevel

Simulate multilevel data with specified within group and between group correlations