Procedures for Psychological, Psychometric, and Personality Research
A package for personality, psychometric, and psychological research
Find two estimates of reliability: Cronbach's alpha and Guttman's Lamb...
Model comparison for regression, mediation, cluster and factor analysi...
Decision Theory measures of specificity, sensitivity, and d prime
The Bass-Ackward factoring algorithm discussed by Goldberg
A bootstrap aggregation function for choosing most predictive unit wei...
Draw pairs of bargraphs based on two groups
Seven data sets showing a bifactor solution.
Find large correlation matrices by stitching together smaller ones fou...
Draw biplots of factor or component scores by factor or component load...
Create a block randomized structure for n independent variables
Bock and Liberman (1970) data set of 1000 observations of the LSAT
Apply four tests of circumplex versus simple structure
Find correlations of composite variables (corrected for overlap) from ...
cluster Fit: fit of the cluster model to a correlation matrix
Find item by cluster correlations, corrected for overlap and reliabili...
Plot factor/cluster loadings and assign items to clusters by their hig...
Convert a cluster vector (from e.g., kmeans) to a keys matrix suitable...
Find Cohen d and confidence intervals
Convert base rates of two diagnoses and their comorbidity into phi, Yu...
Matrix and profile congruences and distances
Bootstrapped and normal confidence intervals for raw and composite cor...
Create an image plot for a correlation or factor matrix
Smooth a non-positive definite correlation matrix to make it positive ...
The sample size weighted correlation may be used in correlating aggreg...
Convert correlations to distances (necessary to do multidimensional sc...
Find a Full Information Maximum Likelihood (FIML) correlation or covar...
Find the correlations, sample sizes, and probability values between el...
Find dis-attenuated correlations given correlations and reliabilities
Bartlett's test that a correlation matrix is an identity matrix
Chi square tests of whether a single matrix is an identity matrix, or ...
Functions for analysis of circadian or diurnal data
Count number of pairwise cases for a data set with missing (NA) data a...
Simulate the C(ues) T(endency) A(ction) model of motivation
Create a 'violin plot' or density plot of the distribution of a set of...
Deprecated Exploratory Factor analysis functions. Please use fa
Basic summary statistics by group
Basic descriptive statistics useful for psychometrics
Helper functions for drawing path model diagrams
Draw a correlation ellipse and two normal curves to demonstrate tetrac...
Create dummy coded variables
8 cognitive variables used by Dwyer for an example.
Convert eigen vectors and eigen values to the more normal (for psychol...
Plot data and 1 and 2 sigma correlation ellipses
Plot means and confidence intervals for multiple groups
Plot means and confidence intervals
Two way plots of means, error bars, and sample sizes
Plot x and y error bars
Show a dot.chart with error bars for different groups or variables
Perform and Exploratory Structural Equation Model (ESEM) by using fact...
Graph factor loading matrices
Apply Dwyer's factor extension to find factor loadings for extended va...
A set of functions for factorial and empirical scale construction
Scree plots of data or correlation matrix compared to random ``paralle...
A first approximation to Random Effects Exploratory Factor Analysis
Exploratory Factor analysis using MinRes (minimum residual) as well as...
Sort factor analysis or principal components analysis loadings
Correlations between two factor analysis solutions
Coefficient of factor congruence
How well does the factor model fit a correlation matrix. Part of the V...
Find R = F F' + U2 is the basic factor model
R* = R- F F'
``Hand" rotate a factor loading matrix
Various ways to estimate factor scores for the factor analysis model
Find various goodness of fit statistics for factor analysis and princi...
Extract cluster definitions from factor loadings
Multi level (hierarchical) factor analysis
Multiple rotations of factor loadings to find local minima
Transformations of r, d, and t including Fisher r to z and z to r and ...
Parse and extend formula input from a model and return the DV(s), IV(s...
Data from the sexism (protest) study of Garcia, Schmitt, Branscome, an...
Find the geometric mean of a vector or columns of a data.frame.
Find the greatest lower bound to reliability.
Alternative estimates of test reliabiity
Find the harmonic mean of a vector, matrix, or columns of a data.frame
Combine calls to head and tail
Intraclass Correlations (ICC1, ICC2, ICC3 from Shrout and Fleiss)
Function to form hierarchical cluster analysis of items
Draw an ICLUST hierarchical cluster structure diagram
create control code for ICLUST graphical output
iclust: Item Cluster Analysis -- Hierarchical cluster analysis using p...
Draw an ICLUST graph using the Rgraphviz package
Sort items by absolute size of cluster loadings
Find the interpolated sample median, quartiles, or specific quantiles ...
Item Response Analysis by Exploratory Factor Analysis of tetrachoric/p...
Simple function to estimate item difficulties using IRT concepts
Item Response Theory estimate of theta (ability) using a Rasch (like) ...
Plot probability of multiple choice responses as a function of a laten...
Apply the Kaiser normalization when rotating factors
Find Cohen's kappa and weighted kappa coefficients for correlation of ...
Find the Kaiser, Meyer, Olkin Measure of Sampling Adequacy
Multiple Regression, Canonical and Set Correlation from matrix or raw ...
Logistic transform from x to p and logit transform from p to x
Combine two square matrices to have a lower off diagonal for one, uppe...
Create a keys matrix for use by score.items or cluster.cor
"Manhattan" plots of correlations with a set of criteria.
Sort the elements of a correlation matrix to reflect factor loadings
A function to add two vectors or matrices
Estimate and display direct and indirect effects of mediators and mode...
Miscellaneous helper functions for the psych package
Find correlations for mixtures of continuous, polytomous, and dichotom...
Find von Neuman's Mean Square of Successive Differences
Multiple histograms with density and normal fits on one page
Find and plot various reliability/gneralizability coefficients for mul...
Graph hierarchical factor structures
Calculate McDonald's omega estimates of general and total factor satur...
Find and graph Mahalanobis squared distances to detect outliers
Find the probability of replication for an F, t, or r and estimate eff...
Test the difference between (un)paired correlations
SPLOM, histograms and correlations for a data matrix
Find miniscales (parcels) of size 2 or 3 from a set of items
Find the partial correlations for a set (x) of variables with set (y) ...
A simple demonstration of the Pearson, phi, and polychoric corelation
Find the phi coefficient of correlation between two dichotomous variab...
Convert a phi coefficient to a tetrachoric correlation
Compute the Moore-Penrose Pseudo Inverse of a matrix
Plotting functions for the psych package of class ``psych"
Convert Cartesian factor loadings into polar coordinates
Phi or Yule coefficient matrix to polychoric coefficient matrix
Prediction function for factor analysis, principal components (pca), b...
Find the predicted validities of a set of scales based on item statist...
Principal components analysis (PCA)
Print and summary functions for the psych class
Perform Procustes,bifactor, promax or targeted rotations and return th...
Tests of significance for correlations
Correct correlations for restriction of range. (Thorndike Case 2)
Reports 7 different estimates of scale reliabity including alpha, omeg...
Function to convert scores to ``conventional " metrics
Extract residuals from various psych objects
Reverse the coding of selected items prior to scale analysis
Root Mean Squared Error of Approximation from chisq, df, and n
Three measures of the correlations between sets of variables
Test the adequacy of simple choice, logistic, or Thurstonian scaling.
Draw a scatter plot with associated X and Y histograms, densities and ...
12 variables created by Schmid and Leiman to show the Schmid-Leiman Tr...
Apply the Schmid Leiman transformation to a correlation matrix
Score scales and find Cronbach's alpha as well as associated statistic...
Find Item Response Theory (IRT) based scores for dichotomous or polyto...
Score item composite scales and find Cronbach's alpha, Guttman lambda ...
Score multiple choice items and provide basic test statistics
Score items using regression or correlation based weights
A utility for basic data cleaning and recoding. Changes values outside...
Find the Standard deviation for a vector, matrix, or data.frame - do n...
Simulate a 3 way balanced ANOVA or linear model, with or without repea...
Simulate a congeneric data set with or without minor factors
Create a population or sample correlation matrix, perhaps with hierarc...
Functions to simulate psychological/psychometric data.
Generate simulated data structures for circumplex, spherical, or simpl...
Simulate multilevel data with specified within group and between group...
Further functions to simulate psychological/psychometric data.
Functions to simulate psychological/psychometric data.
Create correlation matrices or data matrices with a particular measure...
create VSS like data
Simulations of circumplex and simple structure
Calculate univariate or multivariate (Mardia's test) skew and kurtosis...
Find the Squared Multiple Correlation (SMC) of each variable with the ...
Make "radar" or "spider" plots.
Find statistics (including correlations) within and between groups for...
Draw a structural equation model specified by two measurement models a...
Create factor model matrices from an input list
Form a super matrix from two sub matrices.
Convert a table with counts to a matrix or data.frame representing tho...
A simple demonstration (and test) of various IRT scoring algorthims.
Testing of functions in the psych package
Find various test-retest statistics, including test, person and item r...
Tetrachoric, polychoric, biserial and polyserial correlations from var...
Thurstone Case V scaling
Find the trace of a square matrix
Several indices of the unidimensionality of a set of variables.
Compare real and random VSS solutions
Plot VSS fits
Apply the Very Simple Structure, MAP, and other criteria to determine ...
Plot the successive eigen values for a scree test
Find the Winsorized scores, means, sds or variances for a vector, matr...
From a two by two table, find the Yule coefficients of association, co...
A general purpose toolbox developed originally 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. Validation and cross validation of scales developed using basic machine learning algorithms are provided, as are functions for simulating and testing particular item and test structures. Several functions serve as a useful front end for structural equation modeling. Graphical displays of path diagrams, including mediation models, 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 <https://personality-project.org/r/> web page.