Sort factor analysis or principal components analysis loadings
Calculate univariate or multivariate (Mardia's test) skew and kurtosis for a vector, matrix, or data.frame
A data set from Cushny and Peebles (1905) on the effect of three drugs on hours of sleep, used by Student (1908)
Apply the Schmid Leiman transformation to a correlation matrix
9 Cognitive variables discussed by Tucker and Lewis (1973)
Plotting functions for the psych package of class ``psych"
Test the adequacy of simple choice, logistic, or Thurstonian scaling.
Alternative estimates of test reliabiity
Correlations of eight physical variables (from Harman, 1966)
Find two estimates of reliability: Cronbach's alpha and Guttman's Lambda 6.
Example data set from Gorsuch (1997) for an example factor extension.
Find the Standard deviation for a vector, matrix, or data.frame - do not return error if there are no cases
A set of functions for factorial and empirical scale construction
Seven data sets showing a bifactor solution.
Plot the successive eigen values for a scree test
create control code for ICLUST graphical output
Plot data and 1 and 2 sigma correlation ellipses
Convert a cluster vector (from e.g., kmeans) to a keys matrix suitable for scoring item clusters.
Draw an ICLUST graph using the Rgraphviz package
Intraclass Correlations (ICC1, ICC2, ICC3 from Shrout and Fleiss)
Find a Full Information Maximum Likelihood (FIML) correlation or covariance matrix from a data matrix with missing data
Extract cluster definitions from factor loadings
16 ability items scored as correct or incorrect.
Find the correlations, sample sizes, and probability values between elements of a matrix or data.frame.
cluster Fit: fit of the cluster model to a correlation matrix
Basic summary statistics by group
Bock and Liberman (1970) data set of 1000 observations of the LSAT
Bootstrapped confidence intervals for raw and composite correlations
Eysenck Personality Inventory (EPI) data for 3570 participants
Plot means and confidence intervals for multiple groups
Perform bifactor, promax or targeted rotations and return the inter factor angles.
Two data sets of affect and arousal scores as a function of personality and movie conditions
Apply the Very Simple Structure, MAP, and other criteria to determine the appropriate number of factors.
Fisher r to z and z to r and confidence intervals
Find the Kaiser, Meyer, Olkin Measure of Sampling Adequacy
Function to form hierarchical cluster analysis of items
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
Example data from Gleser, Cronbach and Rajaratnam (1965) to show basic principles of generalizability theory.
Find miniscales (parcels) of size 2 or 3 from a set of items
Draw biplots of factor or component scores by factor or component loadings
Plot means and confidence intervals
US family income from US census 2008
``Hand" rotate a factor loading matrix
5 socio-economic variables from Harman (1967)
Compare real and random VSS solutions
R* = R- F F'
75 mood items from the Motivational State Questionnaire for 3896 participants
Miscellaneous helper functions for the psych package
Galton's Mid parent child height data
Create dummy coded variables
Plot VSS fits
Apply four tests of circumplex versus simple structure
Find correlations of composite variables (corrected for overlap) from a larger matrix.
A data.frame of the Galton (1888) height and cubit data set.
Plot x and y error bars
13 personality scales from the Eysenck Personality Inventory and Big 5 inventory
Smooth a non-positive definite correlation matrix to make it positive definite
Find Cohen's kappa and weighted kappa coefficients for correlation of two raters
Scree plots of data or correlation matrix compared to random ``parallel" matrices
Convert eigen vectors and eigen values to the more normal (for psychologists) component loadings
Create a block randomized structure for n independent variables
Score scales and find Cronbach's alpha as well as associated statistics
Galton`s Peas
11 emotional variables from Burt (1915)
Eight political variables used by Harman (1967) as example 8.17
Bartlett's test that a correlation matrix is an identity matrix
How well does the factor model fit a correlation matrix. Part of the VSS package
Find item by cluster correlations, corrected for overlap and reliability
Find the greatest lower bound to reliability.
Find the partial correlations for a set (x) of variables with set (y) removed.
Function to convert scores to ``conventional
" metrics
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 the harmonic mean of a vector, matrix, or columns of a data.frame
Distances between 11 US cities
Draw pairs of bargraphs based on two groups
The sample size weighted correlation may be used in correlating aggregated data
shortcut for reading from the clipboard
Create an image plot for a correlation or factor matrix
Multi level (hierarchical) factor analysis
Two way plots of means, error bars, and sample sizes
Find and graph Mahalanobis squared distances to detect outliers
Sort items by absolute size of cluster loadings
iclust: Item Cluster Analysis -- Hierarchical cluster analysis using psychometric principles
Find Item Response Theory (IRT) based scores for dichotomous or polytomous items
Galton's example of the relationship between height and 'cubit' or forearm length
Bond's Logical Operations Test -- BLOT
Convert a data frame, correlation matrix, or factor analysis output to a LaTeX table
Find R = F F' + U2 is the basic factor model
Apply Dwyer's factor extension to find factor loadings for extended variables
Find the phi coefficient of correlation between two dichotomous variables
Count number of pairwise cases for a data set with missing (NA) data.
Helper functions for drawing path model diagrams
Calculate McDonald's omega estimates of general and total factor saturation
Create a 'violin plot' or density plot of the distribution of a set of variables
Item Response Analysis by Exploratory Factor Analysis of tetrachoric/polychoric correlations
Combine two square matrices to have a lower off diagonal for one, upper off diagonal for the other
Find dis-attenuated correlations given correlations and reliabilities
Find correlations for mixtures of continuous, polytomous, and dichotomous variables
Basic descriptive statistics useful for psychometrics
A package for personality, psychometric, and psychological research
Find the geometric mean of a vector or columns of a data.frame.
Find various goodness of fit statistics for factor analysis and principal components
Find the probability of replication for an F, t, or r and estimate effect size
Coefficient of factor congruence
A utility for basic data cleaning and recoding. Changes values outside of minimum and maximum limits to NA.
Plot probability of multiple choice responses as a function of a latent trait
Draw a scatter plot with associated X and Y histograms, densitie and correlation
Simple function to estimate item difficulties using IRT concepts
Convert correlations to distances (necessary to do multidimensional scaling of correlation data)
Apply the Kaiser normalization when rotating factors
25 Personality items representing 5 factors
SPLOM, histograms and correlations for a data matrix
Test the difference between (un)paired correlations
Functions for analysis of circadian or diurnal data
Graph factor loading matrices
Extract residuals from various psych objects
Find the interpolated sample median, quartiles, or specific quantiles for a vector, matrix, or data frame
Prediction function for factor analysis or principal components
Plot factor/cluster loadings and assign items to clusters by their highest loading.
16 multiple choice IQ items
Simulate a 3 way balanced ANOVA or linear model, with or without repeated measures.
Simulate the C(ues) T(endency) A(ction) model of motivation
Various ways to estimate factor scores for the factor analysis model
Phi or Yule coefficient matrix to polychoric coefficient matrix
A function to add two vectors or matrices
Find statistics (including correlations) within and between groups for basic multilevel analyses
Print and summary functions for the psych class
Combine calls to head and tail
Reverse the coding of selected items prior to scale analysis
8 cognitive variables used by Dwyer for an example.
3 Measures of ability: SATV, SATQ, ACT
Convert a phi coefficient to a tetrachoric correlation
A simple demonstration of the Pearson, phi, and polychoric corelation
Multiple histograms with density and normal fits on one page
Correct correlations for restriction of range. (Thorndike Case 2)
Exploratory Factor analysis using MinRes (minimum residual) as well as EFA by Principal Axis, Weighted Least Squares or Maximum Likelihood
Logistic transform from x to p and logit transform from p to x
Estimate and display direct and indirect effects of mediators and moderator in path models
Draw an ICLUST hierarchical cluster structure diagram
Sort the elements of a correlation matrix to reflect factor loadings
Create a keys matrix for use by score.items or cluster.cor
Item Response Theory estimate of theta (ability) using a Rasch (like) model
create VSS like data
Tests of significance for correlations
Convert Cartesian factor loadings into polar coordinates
Graph hierarchical factor structures
Create factor model matrices from an input list
Score multiple choice items and provide basic test statistics
Score item composite scales and find Cronbach's alpha, Guttman lambda 6 and item whole correlations
An example of the distinction between within group and between group correlations
Create a population or sample correlation matrix, perhaps with hierarchical structure.
Principal components analysis (PCA)
Simulate a congeneric data set
Tetrachoric, polychoric, biserial and polyserial correlations from various types of input
Draw a structural equation model specified by two measurement models and a structural model
Set Correlation and Multiple Regression from matrix or raw input
Testing of functions in the psych package
Find the Winsorized scores, means, sds or variances for a vector, matrix, or data.frame
Simulations of circumplex and simple structure
Simulate multilevel data with specified within group and between group correlations
NEO correlation matrix from the NEO_PI_R manual
Generate simulated data structures for circumplex, spherical, or simple structure
Functions to simulate psychological/psychometric data.
Paired comparison of preferences for 9 vegetables
Create correlation matrices or data matrices with a particular measurement and structural model
Find the trace of a square matrix
Find the Squared Multiple Correlation (SMC) of each variable with the remaining variables in a matrix
Convert a table with counts to a matrix or data.frame representing those counts.
Make "radar" or "spider" plots.
Form a super matrix from two sub matrices.
Thurstone Case V scaling
Two data sets from Harman (1967). 9 cognitive variables from Holzinger and 8 emotional variables from Burt
Convert base rates of two diagnoses and their comorbidity into phi, Yule, and tetrachorics
Find von Neuman's Mean Square of Successive Differences