LISREL offers an impressive array of facilities for data analysis, including indirect and total effects and their standard errors; direct specification of mean parameters; a Ridge Option for handling covariance and correlation matrices that are not positive-definitive; and modification indices for all iterative estimation methods.
LISREL 9.1 includes a number of new features.
Combining LISREL and PRELIS functionality
Modern structural equation modeling is based on raw data. With LISREL 9.1, if raw data is available in a LISREL data system file or in a text file, one can read the data into LISREL and formulate the model using either SIMPLIS syntax or LISREL syntax. It is no longer necessary to estimate an asymptotic covariance matrix with PRELIS and read this into LISREL. The estimation of the asymptotic covariance matrix and the model is now done in LISREL9. One can also use the EM or MCMC multiple imputation methods in LISREL to fit a model to the imputed data.
If requested, LISREL 9.1 will automatically perform robust estimation of standard errors and chi-square goodness of fit measures under non-normality. If the data contain missing values, LISREL 9 will automatically use Full information maximum likelihood (FIML) to estimate the model. Alternatively, users may choose to impute the missing values by EM or MCMC and estimate the model based on the imputed data. Several new sections of the output are also included.
FIML for ordinal and continuous variables
LISREL 9.1 supports Structural Equation Modeling for a mixture of ordinal and continuous variables for simple random samples and complex survey data.
The LISREL implementation allows for the use of design weights to fit SEM models to a mixture of continuous and ordinal manifest variables with or without missing values with optional specification of stratum and/or cluster variables. It also deals with the issue of robust standard error estimation and the adjustment of the chi-square goodness of fit statistic.
This method is based on adaptive quadrature and a user can specify any one of the following four link functions:
Three-level Multilevel Generalized Linear Models
Cluster or multi-stage samples designs are frequently used for populations with an inherent hierarchical structure. Ignoring the hierarchical structure of data has serious implications. The use of alternatives such as aggregation and disaggregation of information to another level can induce an increase in co-linearity among predictors and large or biased standard errors for the estimates.
The collection of models called Generalized Linear Models (GLIMs) have become important, and practical, statistical tools. The basic idea of GLIMs is an adaption of standard regreSSIon to quite different kinds of data. The variables may be dichotomous, ordinal (as with a 5-point Likert scale), counts (number of arrest records), or nominal. The motivation is to tailor the regreSSIon relationship connecting the outcome to relevant independent variables so that it is appropriate to the properties of the dependent variable. The statistical theory and methods for fitting Generalized Linear Models (GLIMs) to survey data was implemented in LISREL 8.8. Researchers from the social and economic sciences are often applying these methods to multilevel data and consequently, inappropriate results are obtained. The LISREL 9.1 statistical module for the analysis of multilevel data allows for design weights. Two estimation methods, MAP (maximization of the posterior distribution) and QUAD (adaptive quadrature) for fitting generalized linear models to multilevel data are available. The LISREL module allows for a wide variety of sampling distributions and link functions.
Four and Five-level Multilevel Linear Models for continuous outcome variables
Social science research often entails the analysis of data with a hierarchical structure. A frequently cited example of multilevel data is a dataset containing measurements on children nested within schools, with schools nested within education departments.
The need for statistical models that take account of the sampling scheme is well recognized and it has been shown that the analysis of survey data under the assumption of a simple random sampling scheme may give rise to misleading results.
Multilevel models are particularly useful in the modeling of data from complex surveys. Cluster or multi-stage samples designs are frequently used for populations with an inherent hierarchical structure. Ignoring the hierarchical structure of data has serious implications. The use of alternatives such as aggregation and disaggregation of information to another level can induce an increase in co-linearity among predictors and large or biased standard errors for the estimates. In order to address concerns regarding the appropriate analyses of survey data, the LISREL multilevel module for continuous data now also handles up to five levels and features an option for users to include design weights on levels 1, 2 , 3, 4 or 5 of the hierarchy.
New filename extensions
All LISREL syntax files have extension .lis (previously .ls8), all PRELIS syntax files have extension .prl (previously .pr2). The LISREL spreadsheet has been renamed LISREL data system file and has extension .lsf (previously .psf)
To ensure backwards compatibility, users can still run previously created syntax files using a .psf file, but to open an existing .psf file using the graphical user’s interface, the user has to rename it to .lsf.
Running LISREL in batch mode
Any of the LISREL programs can be run into batch mode by using a .bat file with the following script:
"c:\program files (x86)\LISREL9\MLISREL9" <program name> <syntax file> <output file>
Program name = LISREL, PRELIS, MULTILEV, MAPGLIM or SURVEYGLIM
Included with LISREL is PRELIS, a pre-processor for LISREL which greatly improves and accelerates analysis of binary, categorical, ordinal, censored, continuous, and/or incomplete data. New features of PRELIS include: missing values on a variable that may be inputted by matching on other variables, new variables that may be created as functions of other variables, tests of univariate and multivariate normality that are obtained for all continuous variables and more.