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