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