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