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