Draw biplots of factor or component scores by factor or component loadings
Model comparison for regression, mediation, and factor analysis
A package for personality, psychometric, and psychological research
Decision Theory measures of specificity, sensitivity, and d prime
Create a block randomized structure for n independent variables
Plot factor/cluster loadings and assign items to clusters by their highest loading.
Convert a cluster vector (from e.g., kmeans) to a keys matrix suitable for scoring item clusters.
Apply four tests of circumplex versus simple structure
Find the correlations, sample sizes, and probability values between elements of a matrix or data.frame.
Compare real and random VSS solutions
Intraclass Correlations (ICC1, ICC2, ICC3 from Shrout and Fleiss)
Find the Standard deviation for a vector, matrix, or data.frame - do not return error if there are no cases
Data from the sexism (protest) study of Garcia, Schmitt, Branscome, and Ellemers (2010)
Find a Full Information Maximum Likelihood (FIML) correlation or covariance matrix from a data matrix with missing data
Plot means and confidence intervals
iclust: Item Cluster Analysis -- Hierarchical cluster analysis using psychometric principles
Find the Kaiser, Meyer, Olkin Measure of Sampling Adequacy
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.
Example data set from Gorsuch (1997) for an example factor extension.
Logistic transform from x to p and logit transform from p to x
Find dis-attenuated correlations given correlations and reliabilities
Compute the Moore-Penrose Pseudo Inverse of a matrix
``Hand" rotate a factor loading matrix
12 variables created by Schmid and Leiman to show the Schmid-Leiman Transformation
Multiple rotations of factor loadings to find local minima
Plot means and confidence intervals for multiple groups
Five data sets from Harman (1967). 9 cognitive variables from Holzinger and 8 emotional variables from Burt
Function to form hierarchical cluster analysis of items
Scree plots of data or correlation matrix compared to random ``parallel" matrices
A first approximation to Random Effects Exploratory Factor Analysis
9 Cognitive variables discussed by Tucker and Lewis (1973)
Bootstrapped and normal confidence intervals for raw and composite correlations
Plot the successive eigen values for a scree test
Plot VSS fits
Apply the Very Simple Structure, MAP, and other criteria to determine the appropriate number of factors.
Draw an ICLUST graph using the Rgraphviz package
Find Cohen's kappa and weighted kappa coefficients for correlation of two raters
Smooth a non-positive definite correlation matrix to make it positive definite
Find the greatest lower bound to reliability.
Sort factor analysis or principal components analysis loadings
25 Personality items representing 5 factors
Find the probability of replication for an F, t, or r and estimate effect size
Find various goodness of fit statistics for factor analysis and principal components
Combine calls to head and tail
create control code for ICLUST graphical output
Simulate the C(ues) T(endency) A(ction) model of motivation
Coefficient of factor congruence
Example data from Gleser, Cronbach and Rajaratnam (1965) to show basic principles of generalizability theory.
Further functions to simulate psychological/psychometric data.
Functions to simulate psychological/psychometric data.
Draw pairs of bargraphs based on two groups
Seven data sets showing a bifactor solution.
Convert eigen vectors and eigen values to the more normal (for psychologists) component loadings
12 cognitive variables from Cattell (1963)
Bock and Liberman (1970) data set of 1000 observations of the LSAT
Find various test-retest statistics, including test, person and item reliability
Perform Procustes,bifactor, promax or targeted rotations and return the inter factor angles.
8 cognitive variables used by Dwyer for an example.
Root Mean Squared Error of Approximation from chisq, df, and n
How well does the factor model fit a correlation matrix. Part of the VSS package
A simple demonstration (and test) of various IRT scoring algorthims.
Find two estimates of reliability: Cronbach's alpha and Guttman's Lambda 6.
Find correlations of composite variables (corrected for overlap) from a larger matrix.
Find the geometric mean of a vector or columns of a data.frame.
Sort items by absolute size of cluster loadings
Convert correlations to distances (necessary to do multidimensional scaling of correlation data)
The Bass-Ackward factoring algorithm discussed by Goldberg
Create an image plot for a correlation or factor matrix
cluster Fit: fit of the cluster model to a correlation matrix
A bootstrap aggregation function for choosing most predictive unit weighted items
Find item by cluster correlations, corrected for overlap and reliability
The sample size weighted correlation may be used in correlating aggregated data
Create a 'violin plot' or density plot of the distribution of a set of variables
Generate simulated data structures for circumplex, spherical, or simple structure
Find the partial correlations for a set (x) of variables with set (y) removed.
Find large correlation matrices by stitching together smaller ones found more rapidly
Simple function to estimate item difficulties using IRT concepts
Find Cohen d and confidence intervals
Matrix and profile congruences and distances
Deprecated Exploratory Factor analysis functions. Please use fa
Count number of pairwise cases for a data set with missing (NA) data and impute values.
Basic summary statistics by group
Multi level (hierarchical) factor analysis
Convert base rates of two diagnoses and their comorbidity into phi, Yule, and tetrachorics
Various ways to estimate factor scores for the factor analysis model
Create a keys matrix for use by score.items or cluster.cor
Chi square tests of whether a single matrix is an identity matrix, or a pair of matrices are equal.
Helper functions for drawing path model diagrams
Exploratory Factor analysis using MinRes (minimum residual) as well as EFA by Principal Axis, Weighted Least Squares or Maximum Likelihood
Bartlett's test that a correlation matrix is an identity matrix
Apply Dwyer's factor extension to find factor loadings for extended variables
Item Response Theory estimate of theta (ability) using a Rasch (like) model
Plot data and 1 and 2 sigma correlation ellipses
Estimate and display direct and indirect effects of mediators and moderator in path models
create VSS like data
Draw a correlation ellipse and two normal curves to demonstrate tetrachoric correlation
Test the adequacy of simple choice, logistic, or Thurstonian scaling.
Two way plots of means, error bars, and sample sizes
Score items using regression or correlation based weights
Plot probability of multiple choice responses as a function of a latent trait
Functions for analysis of circadian or diurnal data
SPLOM, histograms and correlations for a data matrix
Sort the elements of a correlation matrix to reflect factor loadings
Create dummy coded variables
Reports 7 different estimates of scale reliabity including alpha, omega, split half
Combine two square matrices to have a lower off diagonal for one, upper off diagonal for the other
Correlations between two factor analysis solutions
Extract residuals from various psych objects
Convert a phi coefficient to a tetrachoric correlation
Plot x and y error bars
A set of functions for factorial and empirical scale construction
Find the interpolated sample median, quartiles, or specific quantiles for a vector, matrix, or data frame
Apply the Kaiser normalization when rotating factors
Transformations of r, d, and t including Fisher r to z and z to r and confidence intervals
A function to add two vectors or matrices
Basic descriptive statistics useful for psychometrics
Show a dot.chart with error bars for different groups or variables
Plotting functions for the psych package of class ``psych"
Perform and Exploratory Structural Equation Model (ESEM) by using factor extension techniques
R* = R- F F'
Find and graph Mahalanobis squared distances to detect outliers
"Manhattan" plots of correlations with a set of criteria.
Find R = F F' + U2 is the basic factor model
Multiple histograms with density and normal fits on one page
Calculate McDonald's omega estimates of general and total factor saturation
Graph hierarchical factor structures
Find the phi coefficient of correlation between two dichotomous variables
Convert Cartesian factor loadings into polar coordinates
Create a population or sample correlation matrix, perhaps with hierarchical structure.
Test the difference between (un)paired correlations
Alternative estimates of test reliabiity
Extract cluster definitions from factor loadings
Find the harmonic mean of a vector, matrix, or columns of a data.frame
Make "radar" or "spider" plots.
Find and plot various reliability/gneralizability coefficients for multilevel data
Prediction function for factor analysis, principal components (pca), bestScales
Find miniscales (parcels) of size 2 or 3 from a set of items
Find von Neuman's Mean Square of Successive Differences
Score scales and find Cronbach's alpha as well as associated statistics
A simple demonstration of the Pearson, phi, and polychoric corelation
Graph factor loading matrices
Parse and exten formula input from a model and return the DV, IV, and associated terms.
Find the predicted validities of a set of scales based on item statistics
Find correlations for mixtures of continuous, polytomous, and dichotomous variables
Phi or Yule coefficient matrix to polychoric coefficient matrix
Calculate univariate or multivariate (Mardia's test) skew and kurtosis for a vector, matrix, or data.frame
Find Item Response Theory (IRT) based scores for dichotomous or polytomous items
Apply the Schmid Leiman transformation to a correlation matrix
Create correlation matrices or data matrices with a particular measurement and structural model
Function to convert scores to ``conventional
" metrics
Item Response Analysis by Exploratory Factor Analysis of tetrachoric/polychoric correlations
A utility for basic data cleaning and recoding. Changes values outside of minimum and maximum limits to NA.
Reverse the coding of selected items prior to scale analysis
Draw an ICLUST hierarchical cluster structure diagram
Functions to simulate psychological/psychometric data.
Find the Squared Multiple Correlation (SMC) of each variable with the remaining variables in a matrix
Create factor model matrices from an input list
Principal components analysis (PCA)
Print and summary functions for the psych class
Multiple Regression, Canonical and Set Correlation from matrix or raw input
Miscellaneous helper functions for the psych package
Find statistics (including correlations) within and between groups for basic multilevel analyses
Simulations of circumplex and simple structure
Score item composite scales and find Cronbach's alpha, Guttman lambda 6 and item whole correlations
3 Measures of ability: SATV, SATQ, ACT
Score multiple choice items and provide basic test statistics
Draw a scatter plot with associated X and Y histograms, densities and correlation
Form a super matrix from two sub matrices.
Simulate a 3 way balanced ANOVA or linear model, with or without repeated measures.
Tests of significance for correlations
Tetrachoric, polychoric, biserial and polyserial correlations from various types of input
Simulate a congeneric data set with or without minor factors
Draw a structural equation model specified by two measurement models and a structural model
Correct correlations for restriction of range. (Thorndike Case 2)
Simulate multilevel data with specified within group and between group correlations
Testing of functions in the psych package
Convert a table with counts to a matrix or data.frame representing those counts.
Find the Winsorized scores, means, sds or variances for a vector, matrix, or data.frame
Data set testing causal direction in presumed media influence
Several indices of the unidimensionality of a set of variables.
Thurstone Case V scaling
Find the trace of a square matrix
An example of the distinction between within group and between group correlations