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