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