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