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