Topic 4 confirmatory factor analysis cfa outlineoverview readings efa vs. 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. I have a 240item test, and, according to the initial model and other authors, i must obtain 24 factors. Cfa isolating true score variability specialized analysesspecialized software estimation techniques running cfa in stata postestimation goodness of fit, residuals. Confirmatory factor analysis demo using stata gui duration.
Stata module to perform confirmatory factor analysis. Rubin discussed testing in factor analysis, and joreskog 1969 introduced confirmatory factor analysis and. Factor analysis in stata a little bit of this, a little. A general approach to confirmatory maximum likelihood. Three of the scores were for reading skills, three others were for. Running a confirmatory factor analysis in stata is a little more complicated. Confirmatory factor analysis with a single factor stata.
Introductory advanced regression analysis, irt, factor analysis and structural equa tion modeling with categorical, censored, and count outcomes topic 3. To numerically present this, you can ask stata for the skew and kurtosis statistics, including pvalues, as we did in section 3. Factor analysis factor analysis is used to uncover the latent structure dimensions of a set of variables. Data analysis with stata 12 tutorial university of texas. Stata module to perform confirmatory factor analysis modeling, statistical software components s457117, boston college department of economics, revised 16 feb 2010. Confirmatory factor analysis cfa is the next step after exploratory factor analysis to determine the factor structure of your dataset. 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. 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. Few things on measurement theory 2 measurement may be defined as assigning numbers to observational units subjects so as to indicate the magnitude. Minitab calculates the factor loadings for each variable in the analysis. With gsems features, you can perform a confirmatory factor analysis cfa and allow for differences between men and women by typing. Exploratory factor analysis 1 practical issues 129 cfa with covariates 142. This document summarizes confirmatory factor analysis and illustrates how to estimate individual models using amos 7. Psychology seminar psych 406 structural equation modeling.
He disagreed with the idea of a one general intelligence factor underlying all test scores. A general approach to confirmatory maximum likelihood factor. The results of the exploratory factor analysis indicate that all five of these items load nicely onto a single latent factor. Discovering structural equation modeling using stata ebook.
In exploratory factor analysis, all measured variables are related to every latent variable. Stata s generalized structural equations model sem command makes it easy to fit models on data comprising groups. The see consist of four domains measured with nine items. What is the most suitable approach for confirmatory factor. Programs such as sem or lisrel make it possible to combine structural equation modeling and confirmatory factor analysis. Exploratory factor analysis if you are not familiar with the syntax for efa using stata, it is also relatively straightforward. Learn to perform confirmatory factor analysis in stata with data. 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. Stata module to perform confirmatory factor analysis modeling, statistical software components s457117, boston college department of economics. 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. The book uses an applicationbased approach to teaching sem. 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.
The following topics are explained in easytounderstand terms. Two factor cfa to begin, we should start on a good note there is in my opinion really good news. Introduction the exact prevalence of urinary incontinence ui in a population seems to vary from population to population and from study to study. What should i do to perform a confirmatory factor analysis. Companion webpage for confirmatory factor analysis book published by guilford press. Confirmatory factor analysis with stata part 2 youtube. A stepbystep approach to using sas for factor analysis. 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. It allows you to specify that factor loadings of lower. Feb 07, 2018 multiple regression using stata video 1 duration.
Exploratory and confirmatory factor analyses for testing. A total of 193 counseling students completed the nine items on. Factor analysis provides information about reliability, item quality. Run the factor command, followed by the rotate command. The tech8 option is used to request that the optimization. Is there a way to relax this assumption and use logistic procedures instead. Factor analysis using stata predict command and get. 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.
Factor analysis table of contents overview 8 data 10 key concepts and terms 10 exploratory factor analysis efa 10 exploratory vs. Robust ml mlr has been introduced into cfa models when this normality assumption is slightly or moderately violated. For examples of running efa in stata, go here or here. Discovering structural equation modeling using stata.
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. These data were collected on 1428 college students complete data on 65 observations and are responses to items on a survey. Confirmatory factor analysis, exploratory factor analysis, malay language, questionnaire for urinary incontinence diagnosis, reliability 1. Generating a factor score rather than a mean or summative score. 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. With cfa, researcher needs to specify both number of factors as well as what variables define the factors. He also used an oblique rotation, allowing the factors to be correlated.
Confirmatory factor analysis illustrated example podcast 9 minutes the scale of ethnocultural empathy see was developed to measure the ethnocultural empathy. Confirmatory factor analysis using stata part 1 youtube. I am trying to do confirmatory factor analysis on data that is coded binary 0 no, 1 yes. 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. The loadings indicate how much a factor explains each variable. This pdf has been generated from sage research methods datasets. Psychology seminar psych 406 structural equation modeling jeffrey d. Ucla suggests using a tetrachoric correlation matrix, which, however, assumes that binary variables reflect underlying continuous variables. Confirmatory factor analysis is just a particular type of sem. The generality of the approach makes it possible to deal with all kinds of solutions. 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. We can start with an example of confirmatory factor analysis using five variables related to.
The covariance matrix for the nine variables was obtained. A monograph, introduction, and tutorial on factor analysis and principal components analysis in quantitative research. Newsom, spring 2017, psy 495 psychological measurement. 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. 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. Introduction to structural equation modeling using stata cair. Three of the scores were for reading skills, three others were for math skills, and the remaining three were for writing skills. Confirmatory factor analysis cfa is a technique within the sem framework that handles the identifiability problem by fixing some of the loadings to 0. Featured is a simple, stepbystep approach to testing structural equation models with latent variables using the calis procedure. The method of choice for such testing is often confirmatory factor analysis cfa. Title example 15 higherorder cfa descriptionremarks and examplesreferencealso see description sem can be used to estimate higherorder con. It is clearly common that people use factor analysis as preparation for regression often with little substantive gain, but thats a different point. Confirmatory factor analysis, and structural equation modeling for categorical, censored, and count outcomes.
Confirmatory factor analysis statalist the stata forum. Comparison of different estimation methods for categorical. A confirmatory factor analysis with three factors was conducted. Small loadings positive or negative indicate that the factor has a.
In the efa we explore the factor structure how the variables relate and group based on intervariable correlations. The results of a reexamination and reanalysis of the reticence scale kelly, keaten, begnal, 1992 will be used as an example of confirmatory factor. Confirmatory factor analysis using amos, lisrel, and mplus. Discovering structural equation modeling using stata, revised. The default is to estimate the model under missing data theory using all available data. In this example, the confirmatory factor analysis cfa model with continuous factor indicators shown in the picture above is estimated. A tutorial on structural equation modeling for analysis of. Data analysis with stata 12 tutorial university of texas at. A tutorial on structural equation modeling for analysis of overlapping symptoms in cooccurring conditions using mplus. It is confirmatory when you want to test specific hypothesis about the structure or the number of dimensions underlying a set of variables i. Introduction to structural equation modeling using stata. Typically using cfa, the observed variables are assumed to be.
Factor analysis statistical associates blue book series. Regressionanalysis, exploratory factoranalysis,regression. In this example, cognitive abilities of 64 students from a middle school were measured. Given the realities of applied research, it was critical to examine these methods with misspecified models. Confirmatory factor analysis cfa is a multivariate statistical procedure that is used to test how well the measured variables represent the number of constructs. 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. Hi, i am testing the factorial construct validity of an instrument which includes 15 likerttype. 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 implementation demonstration extensions cfa1. Using confirmatory factor analysis to measure contemporaneous. The model has two correlated factors that are each measured by three. The fictitious data contain nine cognitive test scores. Factor analysis, in the sense of exploratory factor analysis, is a statistical technique for data reduction. Im trying to perform a confirmatory factor analysis using spss 19. This page contains data and syntax files for most of the examples in the book. This example introduces confirmatory factor analysis cfa. Small loadings positive or negative indicate that the factor has a weak influence on the variable. 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. Large loadings positive or negative indicate that the factor strongly influences the variable. Factor analysis with stata is accomplished in several steps. Please note that a subset of the data is used for some examples.
What is the most suitable approach for confirmatory factor analysis cfa with nonnormal data. This page shows an example factor analysis with footnotes explaining the output. Introductory advanced factor analysis and structural equation modeling with continuous outcomes topic 2. Conducting exploratory factor analysis in stata is relatively straight forward. 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. Factor analysis stata annotated output this page shows an example factor analysis with footnotes explaining the output. Feb 07, 2018 confirmatory factor analysis using stata part 1.
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