Psychometric software refers to specialized programs used for the psychometric analysis of data obtained from tests, questionnaires, polls or inventories that measure latent psychoeducational variables. Although some psychometric analyses can be performed using general statistical software such as SPSS, most require specialized tools designed specifically for psychometric purposes.
Sources of Free Software
Numerous free psychometric tools have been developed by researchers and educators. Notable websites and resources offering such software include:
CASMA at the University of Iowa, USA: Hosts the GENOVA Suite of computer programs for generalizability theory. Software from Harold Doran, PACER: Provides web-based and desktop applications for psychometric analysis. REMP at the University of Massachusetts, USA: Provides item response theory software, with the last update in 2008. Software from Brad Hanson: Offers C++ libraries for item response theory (IRT). Software from John Uebersax: Features latent class analysis software. Software from J. Patrick Meyer, jMetrik: Provides open-source software for psychometric analysis. Software from PMaps: Specializes in psychometric assessment software. Software directory at the Institute for Objective Measurement: Lists various psychometric Software from Matthew Courtney, Kevin Chang, Eric Mei, Kane Meissel, Luke Rowe, and Laila Issayeva. There is also an R Shiny tool for reproducible Rasch analysis, differential item functioning, equating, and examination of group effects.
Additionally, an increasing number of packages for R can be found in the CRAN Task View: Psychometric Models and Methods.
Classical test theory Classical test theory (CTT) is an approach to psychometric analysis that involves fewer assumptions than item response theory and is more suitable for smaller sample sizes.
Autopsych Autopsych is a free and open-source web app with multiple features for conducting Classical Test Theory (CTT) and Rasch modeling. CTT functions include:
Percentage correct Observed scores for each item category Item-total correlations Item-rest correlations (with user-specified confidence intervals) Item-rest point biserial/polyserial correlations Cronbach’s alpha Alpha-if-deleted Full Pearson correlation matrix (item matrix) with levels of statistical significance
Autopsych also performs several Rasch-based functions, including:
Basic Rasch many-facets analysis for differential item functioning (DIF) Fixed item equating for dichotomous item-response matrices One-way ANOVA Inter-rater reliability analysis
CITAS CITAS (Classical Item and Test Analysis Spreadsheet) is a free Excel workbook designed to provide scoring and statistical analysis of classroom tests. Users can type or paste item responses (ABCD) and keys into the workbook, and the output is automatically populated. Unlike some other programs, CITAS does not require any 'running' or experience in psychometric analysis, making it accessible to teachers and professors.
jMetrik jMetrik is free and open-source software for conducting comprehensive psychometric analysis, developed by J. Patrick Meyer at the University of Virginia. It includes methods for:
Classical item analysis Differential item functioning (DIF) analysis Confirmatory factor analysis Item response theory (IRT) IRT equating Nonparametric item response theory
jMetrik's item analysis includes proportion, point biserial, and biserial statistics for all response options. It calculates various reliability coefficients include Cronbach's alpha, Guttman's lambda and the Feldt-Gilmer Coefficient. The DIF analysis uses nonparametric item characteristic curves and the Mantel-Haenszel procedure, reporting effect sizes and ETS DIF classifications. IRT methods include the Rasch, partial credit, and rating scale models, with equating methods like mean/mean, mean/sigma, Haebara, and Stocking-Lord procedures.
jMetrik also features:
IRT illustrator Basic descriptive statistics Graphics facility for bar charts, pie charts, histograms, kernel density estimates, and line plots
jMetrik is a pure Java application that runs on 32-bit and 64-bit versions of Windows, Mac, and Linux operating systems, requires Java 1.6 on the host computer.
Iteman Iteman is a commercial Windows program specifically designed for classical test analysis. It produces tech reports in Microsoft Word with graphics, narratives, and embedded tables. Iteman calculates the proportion and point biserial of each item, high/low subgroup proportions, and detailed item performance graphics. It also provides descriptive statistics, including the mean, standard deviation, reliability, and standard error of measurement, for each domain and the overall tests. Iteman is available from Assessment Systems Corporation.
Lertap Lertap5 (Laboratory of Educational Research Test Analysis Program) is a comprehensive software package for test and survey analyses, developed for Windows and Macintosh computers with Microsoft Excel. Lertap5 includes:
Test, item and option statistics Classification consistency and mastery test analysis Cheating detection procedures Extensive graphics (e.g., trace lines for item options, conditional standard errors of measurement, scree plots, boxplots, histograms, scatterplots)
Lertap5 supports both CTT and Rasch item analysis for dichotomous test items. DIF (differential item functioning) is supported using Mantel-Haenszel methods, with graphical results. It also interfaces with R and R Studio, producing data and control files for various IRT programs like Xcalibre and Bilog MG, and preparing data for SAS.
Lertap5 was developed by Larry Nelson at Curtin University and is available from Lertap5.com.
TAP TAP (Test Analysis Program) is a free Windows program written in Delphi Pascal that performs test and item analyses based on classical test theory. TAP provides reports on examinee total scores, item statistics (e.g., item difficulty, item discrimination, point-biserial), options analyses, and other useful information. It also provides individual examinee reports of total scores and item responses.
ViSta-CITA ViSta-CITA (Classical Item and Test Analysis) is a module within the Visual Statistics System (ViSta) that applies graphical-oriented methods to psychometric analysis. Developed by Ruben Ledesma, J. Gabriel Molina, Pedro M. Valero-Mora, and Forrest W. Young. ViSta has not been updated since 2014.
Psych Psych is an R package providing routines for personality, psychometrics, and experimental psychology. Its functions support:
Scale construction using factor analysis, cluster analysis, and reliability analysis Basic descriptive statistics Item response theory via factor analysis of tetrachoric and polychoric correlations Simulating item and test structures Structural equation modelling
Psych creates graphical displays of path diagrams, factor analysis, and structural equation models using basic graphics. For more information, see the personality-project.org/r webpage.
Item response theory calibration Item response theory (IRT) is a psychometric approach which assumes that the probability of a certain response is a direct function of an underlying trait or traits. Various functions have been proposed to model this relationship, and the different calibration packages reflect this. Several software packages have been developed for additional analysis such as equating; they are listed in the next section.
Autopsych An open-source software program, Autopsych, is used for performing uni-dimensional Rasch analysis. The app can handle both dichotomous and polytomous data via the application of master’s partial credit model. The app adopts marginal maximum likelihood estimation and leverages off a total 31 open-source R packages (including TAM, psych, knitr, etc.). Users upload item-response matrices (.csv files), customize settings for Rasch analysis, and the app automatically generates PDF with embedded narration for methodology and results. Excel files include outputs for all analyses performed including plausible values. Users can also perform basic many-facets Rasch analysis for an examination of item DIF, fixed anchor equating for two dichotomous matrices, an analysis of variance (ANOVA) of EAP theta estimates for examining the effect of group effects, and inter-rater reliability analysis for the examination of examiner consistency. A full exposition of the web app is provided in the journal, PLOS ONE SCIENCE.
BILOG-MG BILOG-MG is a software program for IRT analysis of dichotomous (correct/incorrect) data, including fit and differential item functioning. It is commercial, and only available from Scientific Software International.
Dexter Dexter, first published February 2017, is an R package intended as a robust and fairly comprehensive system for managing and analyzing test data organized in booklets. The package includes facilities for importing and managing test data, assessing and improving the quality of data through basic test-and-item analysis, fitting an IRT model, and computing various estimates of ability. Many psychometric methods not found elsewhere are provided, such as Haberman’s (2007) interaction model generalized for polytomous items, efficient generation of plausible values or scores, new methods for exploratory and confirmatory DIF analysis, support for the 3DC method of standard setting, and many more. The central IRT model is a polytomous generalization of the extended marginal Rasch model. Estimation is by CML or Bayesian techniques. There are two companion packages: dextergui, first published June 2018, and providing an easy graphical interface to the most widely used functions in dexter; and dexterMST, first published July 2018, for managing and analysing data from multi-stage test designs. All packages are extensively documented both for the beginner as for the professional
Facets Facets is a software program for Rasch analysis of rates or judge-intermediated data, such as essay grades, diving competitions, satisfaction surveys and quality-of-life data. Other applications include rank-order data, binomial trials and Poisson counts.
FlexMIRT FlexMIRT IRT software is a multilevel, multiple group software package for item analysis, item calibration, and test scoring. The flexMIRT IRT software package fits a variety of unidimensional and multidimensional item response theory models (also known as item factor analysis models) to single-level and multilevel data in any number of groups.
Irtoys Irtoys is an R package first published in 2007 and supporting almost everything in the book but limited to one booklet of dichotomous items. It is good for teaching, smaller projects, as a psychometrician's Swiss knife and as a source of building stones for other projects. The simple syntax files for ICL and BILOG-MG it writes can be studied and modified to handle more complicated problems.
ICL ICL (IRT Command Language) performs IRT calibrations, including the 1, 2, and 3 parameter logistic models as well as the partial credit model and generalized partial credit model. It can also generate response data. As the name implies, it is completely command code driven, with no graphical user interface.
jMetrik