# psych v1.0-97

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## Procedures for Psychological, Psychometric, and Personality Research

A number of routines for personality, psychometrics and experimental psychology. Functions are primarily for scale construction using factor analysis, cluster analysis and reliability analysis, although others provide basic descriptive statistics. Item Response Theory is done using factor analysis of tetrachoric and polychoric correlations. Functions for simulating particular item and test structures are included. Several functions serve as a useful front end for structural equation modeling. Graphical displays of path diagrams, factor analysis and structural equation models are created using basic graphics. Some of the functions are written to support a book on psychometrics as well as publications in personality research. For more information, see the personality-project.org/r webpage.

## Functions in psych

 Name Description iclust iclust: Item Cluster Analysis -- Hierarchical cluster analysis using psychometric principles cortest.bartlett Bartlett's test that a correlation matrix is an identity matrix ICLUST.rgraph Draw an ICLUST graph using the Rgraphviz package factor.residuals R* = R- F F' headtail Combine calls to head and tail alpha Find two estimates of reliability: Cronbach's alpha and Guttman's Lambda 6. bfi 25 Personality items representing 5 factors affect Two data sets of affect and arousal scores as a function of personality and movie conditions geometric.mean Find the geometric mean of a vector or columns of a data.frame. VSS.scree Plot the successive eigen values for a scree test describe.by Basic summary statistics by group circ.tests Apply four tests of circumplex versus simple structure msq 75 mood items from the Motivational State Questionnaire for 3896 participants partial.r Find the partial correlations for a set (x) of variables with set (y) removed. cor.plot Create an image plot for a correlation or factor matrix cortest.mat Chi square tests of whether a single matrix is an identity matrix, or a pair of matrices are equal. ICC Intraclass Correlations (ICC1, ICC2, ICC3 from Shrout and Fleiss) factor.rotate Hand" rotate a factor loading matrix SD Find the Standard deviation for a vector, matrix, or data.frame - do not return error if there are no cases score.multiple.choice Score multiple choice items and provide basic test statistics Dwyer 8 cognitive variables used by Dwyer for an example. Schmid 12 variables created by Schmid and Leiman to show the Schmid-Leiman Transformation iclust.diagram Draw an ICLUST hierarchical cluster structure diagram interp.median Find the interpolated sample median, quartiles, or specific quantiles for a vector, matrix, or data frame reverse.code Reverse the coding of selected items prior to scale analysis VSS.parallel Compare real and random VSS solutions VSS.plot Plot VSS fits fa.sort Sort factor analysis or principal components analysis loadings describe Basic descriptive statistics useful for psychometrics cities Distances between 11 US cities read.clipboard shortcut for reading from the clipboard count.pairwise Count number of pairwise cases for a data set with missing (NA) data. heights A data.frame of the Galton (1888) height and cubit data set. 00.psych A package for personality, psychometric, and psychological research ellipses Plot data and 1 and 2 sigma correlation ellipses mat.sort Sort the elements of a correlation matrix to reflect factor loadings fa.diagram Graph factor loading matrices winsor Find the Winsorized scores, means, sds or variances for a vector, matrix, or data.frame scaling.fits Test the adequacy of simple choice, logistic, or Thurstonian scaling. income US family income from US census 2008 fa.extension Apply Dwyer's factor extension to find factor loadings for extended variables ICLUST.sort Sort items by absolute size of cluster loadings matrix.addition A function to add two vectors or matrices cubits Galton's example of the relationship between height and 'cubit' or forearm length paired.r Test the difference between (un)paired correlations Harman Two data sets from Harman (1967). 9 cognitive variables from Holzinger and 8 emotional variables from Burt epi.bfi 13 personality scales from the Eysenck Personality Inventory and Big 5 inventory biplot.psych Draw biplots of factor or component scores by factor or component loadings block.random Create a block randomized structure for n independent variables logistic Logistic transform from x to p and logit transform from p to x irt.item.diff.rasch Simple function to estimate item difficulties using IRT concepts Promax Perform promax or targeted rotations and return the inter factor angles Bechtoldt Seven data sets showing a bifactor solution. scrub A utility for basic data cleaning and recoding. Changes values outside of minimum and maximum limits to NA. fisherz Fisher r to z and z to r and confidence intervals table2matrix Convert a table with counts to a matrix or data.frame representing those counts. pairs.panels SPLOM, histograms and correlations for a data matrix blot Bond's Logical Operations Test -- BLOT sim.item Generate simulated data structures for circumplex or simple structure cluster2keys Convert a cluster vector (from e.g., kmeans) to a keys matrix suitable for scoring item clusters. Gorsuch Example data set from Gorsuch (1997) for an example factor extension. draw.tetra Draw a correlation ellipse and two normal curves to demonstrate tetrachoric correlation irt.fa Item Response Analysis by factor analysis of tetrachoric/polychoric correlations cosinor Functions for analysis of circadian or diurnal data structure.diagram Draw a structural equation model specified by two measurement models and a structural model burt 11 emotional variables from Burt (1915) correct.cor Find dis-attenuated correlations given correlations and reliabilities test.psych Testing of functions in the psych package fa MinRes (minimum residual) Factor analysis as well as Factor Analysis by Principal Axis, Weighted Least Squares or Maximum Likelihood diagram Helper functions for drawing path model diagrams principal Principal components analysis phi Find the phi coefficient of correlation between two dichotomous variables omega Calculate McDonald's omega estimates of general and total factor saturation cluster.loadings Find item by cluster correlations, corrected for overlap and reliability corr.test Find the correlations, sample sizes, and probability values between elements of a matrix or data.frame. error.crosses Plot x and y error bars factor.fit How well does the factor model fit a correlation matrix. Part of the VSS package predict.psych Prediction function for factor analysis or principal components guttman Alternative estimates of test reliabiity omega.graph Graph hierarchical factor structures Yule 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. irt.1p Item Response Theory estimate of theta (ability) using a Rasch (like) model score.alpha Score scales and find Cronbach's alpha as well as associated statistics sim.VSS create VSS like data sat.act 3 Measures of ability: SATV, SATQ, ACT p.rep Find the probability of replication for an F, t, or r and estimate effect size cta Simulate the C(ues) T(endency) A(ction) model of motivation print.psych Print and summary functions for the psych class ICLUST.graph create control code for ICLUST graphical output bock Bock and Liberman (1970) data set of 1000 observations of the LSAT eigen.loadings Convert eigen vectors and eigen values to the more normal (for psychologists) component loadings comorbidity Convert base rates of two diagnoses and their comorbidity into phi, Yule, and tetrachorics r.test Tests of significance for correlations fa.parallel Scree plots of data or correlation matrix compared to random parallel" matrices cluster.fit cluster Fit: fit of the cluster model to a correlation matrix cluster.cor Find correlations of composite variables from a larger matrix peas Galtons Peas error.bars.by Plot means and confidence intervals for multiple groups factor.congruence Coefficient of factor congruence cluster.plot Plot factor/cluster loadings and assign items to clusters by their highest loading. factor.model Find R = F F' + U2 is the basic factor model sim.hierarchical Create a population or sample correlation matrix, perhaps with hierarchical structure. factor2cluster Extract cluster definitions from factor loadings tr Find the trace of a square matrix sim.structure Create correlation matrices or data matrices with a particular measurement and structural model phi.demo A simple demonstration of the Pearson, phi, and polychoric corelation polychor.matrix Phi or Yule coefficient matrix to polychoric coefficient matrix sim.anova Simulate a 3 way balanced ANOVA or linear model, with or without repeated measures. smc Find the Squared Multiple Correlation (SMC) of each variable with the remaining variables in a matrix scatter.hist Draw a scatter plot with associated X and Y histograms, densitie and correlation mixed.cor Find correlations for mixtures of continuous, polytomous, and dichotomous variables cohen.kappa Find Cohen's kappa and weighted kappa coefficients for correlation of two raters mardia Calculate univariate or multivariate (Mardia's test) skew and kurtosis for a vector, matrix, or data.frame plot.psych Plotting functions for the psych package of class psych" score.items Score item composite scales and find Cronbach's alpha, Guttman lambda 6 and item whole correlations super.matrix Form a super matrix from two sub matrices. tetrachoric Tetrachoric, polychoric, biserial and polyserial correlations from various types of input polar Convert Cartesian factor loadings into polar coordinates structure.list Create factor model matrices from an input list phi2poly Convert a phi coefficient to a polychoric correlation sim.congeneric Simulate a congeneric data set factor.stats Find various goodness of fit statistics for factor analysis and principal components VSS Apply the Very Simple Structure and MAP criteria to determine the appropriate number of factors. bi.bars Draw pairs of bargraphs based on two groups error.bars Plot means and confidence intervals multi.hist Multiple histograms with density and normal fits on one page ICLUST.cluster Function to form hierarchical cluster analysis of items Tucker 9 Cognitive variables discussed by Tucker and Lewis (1973) galton Galton's Mid parent child height data make.keys Create a keys matrix for use by score.items or cluster.cor rescale Function to convert scores to conventional " metrics sim Functions to simulate psychological/psychometric data. neo NEO correlation matrix from the NEO_PI_R manual set.cor Set Correlation and Multiple Regression from raw or matrix input iqitems 14 multiple choice IQ items thurstone Thurstone Case V scaling harmonic.mean Find the harmonic mean of a vector, matrix, or columns of a data.frame vegetables Paired comparison of preferences for 9 vegetables glb.algebraic Find the greatest lower bound to reliability. simulation.circ Simulations of circumplex and simple structure No Results!