If you look in the sem manual, examples 1, 3, and 15 will give you a pretty comprehensive view of how to use the sem command for this. Factor analysis using stata predict command and get. Exploratory factor analysis if you are not familiar with the syntax for efa using stata, it is also relatively straightforward. Cfa isolating true score variability specialized analysesspecialized software estimation techniques running cfa in stata postestimation goodness of fit, residuals. Discovering structural equation modeling using stata. Featured is a simple, stepbystep approach to testing structural equation models with latent variables using the calis procedure. The results of a reexamination and reanalysis of the reticence scale kelly, keaten, begnal, 1992 will be used as an example of confirmatory factor. Sem with continuous factor indicators and an indirect effect for factors. Minitab calculates the factor loadings for each variable in the analysis. Factor analysis table of contents overview 8 data 10 key concepts and terms 10 exploratory factor analysis efa 10 exploratory vs. Programs such as sem or lisrel make it possible to combine structural equation modeling and confirmatory factor analysis.
If you are using a version of stata older than 12 which you should have told us in your post, then you will not have an sem command. What is the most suitable approach for confirmatory factor. In exploratory factor analysis, all measured variables are related to every latent variable. Learn to perform confirmatory factor analysis in stata with data. Psychology seminar psych 406 structural equation modeling jeffrey d.
Confirmatory factor analysis cfa and exploratory factor analysis efa are similar techniques, but in exploratory factor analysis efa, data is simply explored and provides information about the numbers of factors required to represent the data. Data analysis with stata 12 tutorial university of texas. In this example, cognitive abilities of 64 students from a middle school were measured. Few things on measurement theory 2 measurement may be defined as assigning numbers to observational units subjects so as to indicate the magnitude. Run the factor command, followed by the rotate command. Confirmatory factor analysis cfa is a multivariate statistical procedure that is used to test how well the measured variables represent the number of constructs. The method of choice for such testing is often confirmatory factor analysis cfa. Typically using cfa, the observed variables are assumed to be. Stata s generalized structural equations model sem command makes it easy to fit models on data comprising groups. Exploratory and confirmatory factor analyses for testing. Factor analysis stata annotated output this page shows an example factor analysis with footnotes explaining the output. The model has two correlated factors that are each measured by three. Confirmatory factor analysis using amos, lisrel, and mplus.
A tutorial on structural equation modeling for analysis of. Confirmatory factor analysis is just a particular type of sem. He disagreed with the idea of a one general intelligence factor underlying all test scores. Stata module to perform confirmatory factor analysis modeling, statistical software components s457117, boston college department of economics. Generating a factor score rather than a mean or summative score. Confirmatory factor analysis, and structural equation modeling for categorical, censored, and count outcomes. For examples of running efa in stata, go here or here.
It reduces attribute space from a larger number of variables to a smaller number of factors and as such is a nondependent procedure that is, it. A general approach to confirmatory maximum likelihood. Running a confirmatory factor analysis in stata is a little more complicated. Small loadings positive or negative indicate that the factor has a weak influence on the variable.
Comparison of different estimation methods for categorical and ordinal data in confirmatory factor analysis in confirmatory factor analysis cfa, which is used quite often for scale development and adaptation studies, the selected estimation method, affects the results obtained from the data. A stepbystep approach to using sas for factor analysis. Stata module to perform confirmatory factor analysis. Factor analysis, in the sense of exploratory factor analysis, is a statistical technique for data reduction. Three of the scores were for reading skills, three others were for math skills, and the remaining three were for writing skills. The tech8 option is used to request that the optimization. The generality of the approach makes it possible to deal with all kinds of solutions. Factor analysis with stata is accomplished in several steps. We describe a general procedure by which any number of parameters of the factor analytic model can be held fixed at any values and the remaining free parameters estimated by the maximum likelihood method. Introduction to structural equation modeling using stata. Factor analysis implementation demonstration extensions cfa1. Is there a way to relax this assumption and use logistic procedures instead. It is confirmatory when you want to test specific hypothesis about the structure or the number of dimensions underlying a set of variables i.
Jul 15, 2015 in confirmatory factor analysis cfa, the use of maximum likelihood ml assumes that the observed indicators follow a continuous and multivariate normal distribution, which is not appropriate for ordinal observed variables. May 01, 2012 confirmatory factor analysis cfa is a hypothesisdriven variant of exploratory factor analysis that is based on measurement theory and represents a special case of structural equation modeling sem bollen, 1989. Using confirmatory factor analysis to measure contemporaneous. The default is to estimate the model under missing data theory using all available data. A tutorial on structural equation modeling for analysis of overlapping symptoms in cooccurring conditions using mplus. Companion webpage for confirmatory factor analysis book published by guilford press. Introduction the exact prevalence of urinary incontinence ui in a population seems to vary from population to population and from study to study. It is clearly common that people use factor analysis as preparation for regression often with little substantive gain, but thats a different point.
Discovering structural equation modeling using stata, revised. It allows you to specify that factor loadings of lower. Title example 15 higherorder cfa descriptionremarks and examplesreferencealso see description sem can be used to estimate higherorder con. Confirmatory factor analysis cfa is a hypothesisdriven variant of exploratory factor analysis that is based on measurement theory and represents a special case of structural equation modeling sem bollen, 1989. What should i do to perform a confirmatory factor analysis. Confirmatory factor analysis demo using stata gui duration. The see consist of four domains measured with nine items. We can start with an example of confirmatory factor analysis using five variables related to. Two factor cfa to begin, we should start on a good note there is in my opinion really good news. Confirmatory factor analysis cfa is the next step after exploratory factor analysis to determine the factor structure of your dataset. Introductory advanced factor analysis and structural equation modeling with continuous outcomes topic 2. The following topics are explained in easytounderstand terms. Confirmatory factor analysis, exploratory factor analysis, malay language, questionnaire for urinary incontinence diagnosis, reliability 1. Feb 07, 2018 multiple regression using stata video 1 duration.
Hi, i am testing the factorial construct validity of an instrument which includes 15 likerttype. Confirmatory factor analysis with a single factor stata. A confirmatory factor analysis with three factors was conducted. We will do an iterated principal axes ipf option with smc as initial communalities retaining three factors factor3 option followed by varimax and promax rotations. Small loadings positive or negative indicate that the factor has a. Please note that a subset of the data is used for some examples. Robust ml mlr has been introduced into cfa models when this normality assumption is slightly or moderately violated. Conducting exploratory factor analysis in stata is relatively straight forward. A total of 193 counseling students completed the nine items on.
Given the realities of applied research, it was critical to examine these methods with misspecified models. The loadings indicate how much a factor explains each variable. Confirmatory factor analysis cfa and exploratory factor analysis efa are similar techniques, but in exploratory factor analysis efa, data is simply explored and provides information about the numbers of factors required to. Three of the scores were for reading skills, three others were for.
Ucla suggests using a tetrachoric correlation matrix, which, however, assumes that binary variables reflect underlying continuous variables. This document summarizes confirmatory factor analysis and illustrates how to estimate individual models using amos 7. Newsom, spring 2017, psy 495 psychological measurement. What is the most suitable approach for confirmatory factor analysis cfa with nonnormal data. Discovering structural equation modeling using stata ebook. Factor analysis statistical associates blue book series. Factor analysis factor analysis is used to uncover the latent structure dimensions of a set of variables. This example introduces confirmatory factor analysis cfa.
He also used an oblique rotation, allowing the factors to be correlated. Measurement theory is the branch of applied mathematics and statistics concerned with the measurement of phenomena in science and. The book uses an applicationbased approach to teaching sem. In confirmatory factor analysis cfa, the use of maximum likelihood ml assumes that the observed indicators follow a continuous and multivariate normal distribution, which is not appropriate for ordinal observed variables. It reduces attribute space from a larger number of variables to a smaller number of factors and as such is a nondependent procedure that is, it does not assume a dependent variable is specified. Large loadings positive or negative indicate that the factor strongly influences the variable. I have a 240item test, and, according to the initial model and other authors, i must obtain 24 factors. Psychology seminar psych 406 structural equation modeling. A monograph, introduction, and tutorial on factor analysis and principal components analysis in quantitative research. I am trying to do confirmatory factor analysis on data that is coded binary 0 no, 1 yes.
This page contains data and syntax files for most of the examples in the book. Im trying to perform a confirmatory factor analysis using spss 19. With gsems features, you can perform a confirmatory factor analysis cfa and allow for differences between men and women by typing. In the efa we explore the factor structure how the variables relate and group based on intervariable correlations.
Confirmatory factor analysis cfa is a technique within the sem framework that handles the identifiability problem by fixing some of the loadings to 0. In this example, the confirmatory factor analysis cfa model with continuous factor indicators shown in the picture above is estimated. Confirmatory factor analysis using stata part 1 youtube. Introduction to structural equation modeling using stata cair. Stata module to perform confirmatory factor analysis modeling, statistical software components s457117, boston college department of economics, revised 16 feb 2010. This page shows an example factor analysis with footnotes explaining the output. Rubin discussed testing in factor analysis, and joreskog 1969 introduced confirmatory factor analysis and.
Data analysis with stata 12 tutorial university of texas at. The covariance matrix for the nine variables was obtained. The results of the exploratory factor analysis indicate that all five of these items load nicely onto a single latent factor. This pdf has been generated from sage research methods datasets. The fictitious data contain nine cognitive test scores. Confirmatory factor analysis illustrated example podcast 9 minutes the scale of ethnocultural empathy see was developed to measure the ethnocultural empathy. A general approach to confirmatory maximum likelihood factor. Exploratory factor analysis 1 practical issues 129 cfa with covariates 142.
Confirmatory factor analysis statalist the stata forum. This monte carlo simulation study examined the performance of full and robust wls for twofactor, eightindicator confirmatory factor analytic models that were either correctly specified, overspecified, or misspecified in one of two ways. Confirmatory factor analysis and structural equation modeling 57 analysis is specified using the knownclass option of the variable command in conjunction with the typemixture option of the analysis command. Confirmatory factor analysis with stata part 2 youtube.
Feb 07, 2018 confirmatory factor analysis using stata part 1. Introductory advanced regression analysis, irt, factor analysis and structural equa tion modeling with categorical, censored, and count outcomes topic 3. These data were collected on 1428 college students complete data on 65 observations and are responses to items on a survey. With cfa, researcher needs to specify both number of factors as well as what variables define the factors. Discovering structural equation modeling using stata, revised edition, by alan acock, successfully introduces both the statistical principles involved in structural equation modeling sem and the use of stata to fit these models. Factor analysis provides information about reliability, item quality. Regressionanalysis, exploratory factoranalysis,regression. My suggestion is that you dont need it with three predictors and that expecting results to have values similar to the response is a misunderstanding of what factor analysis does. I am running factor analysis on stata to reduce a few variables to a single explanatory variable which means experience of a manager should be nonnegative value, however, after using predict command i check the range of the new variable and found that there are many negative values, how do i avoid this. To numerically present this, you can ask stata for the skew and kurtosis statistics, including pvalues, as we did in section 3. Factor analysis in stata a little bit of this, a little. Comparison of different estimation methods for categorical. Topic 4 confirmatory factor analysis cfa outlineoverview readings efa vs.
870 1060 1208 541 83 1461 549 1084 154 1297 776 1132 443 1416 233 15 177 295 429 461 650 376 1410 1380 1001 180 100 601 1275 523