2024年4月26日发(作者：)

Getting Started With Mplus

CHAPTER 2

GETTING STARTED WITH Mplus

After Mplus is installed, the program can be run from the Mplus editor.

The Mplus Editor for Windows includes a language generator and a

graphics module. The graphics module provides graphical displays of

observed data and analysis results.

In this chapter, a brief description of the user language is presented

along with an overview of the examples and some model estimation

considerations.

THE Mplus LANGUAGE

The user language for Mplus consists of a set of ten commands each of

which has several options. The default options for Mplus have been

chosen so that user input can be minimized for the most common types

of analyses. For most analyses, only a small subset of the Mplus

commands is needed. Complicated models can be easily described using

the Mplus language. The ten commands of Mplus are:

• TITLE

• DATA (required)

• VARIABLE (required)

• DEFINE

• ANALYSIS

• MODEL

• OUTPUT

• SAVEDATA

• PLOT

• MONTECARLO

The TITLE command is used to provide a title for the analysis. The

DATA command is used to provide information about the data set to be

analyzed. The VARIABLE command is used to provide information

about the variables in the data set to be analyzed. The DEFINE

command is used to transform existing variables and create new

variables. The ANALYSIS command is used to describe the technical

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details of the analysis. The MODEL command is used to describe the

model to be estimated. The OUTPUT command is used to request

additional output not included as the default. The SAVEDATA

command is used to save the analysis data, auxiliary data, and a variety

of analysis results. The PLOT command is used to request graphical

displays of observed data and analysis results. The MONTECARLO

command is used to specify the details of a Monte Carlo simulation

study.

The Mplus commands may come in any order. The DATA and

VARIABLE commands are required for all analyses. All commands

must begin on a new line and must be followed by a colon. Semicolons

separate command options. There can be more than one option per line.

The records in the input setup must be no longer than 90 columns. They

can contain upper and/or lower case letters and tabs.

Commands, options, and option settings can be shortened for

convenience. Commands and options can be shortened to four or more

letters. Option settings can be referred to by either the complete word or

the part of the word shown in bold type in the command boxes in each

chapter.

Comments can be included anywhere in the input setup. A comment is

designated by an exclamation point. Anything on a line following an

exclamation point is treated as a user comment and is ignored by the

program.

The keywords IS, ARE, and = can be used interchangeably in all

commands except DEFINE, MODEL CONSTRAINT, and MODEL

TEST. Items in a list can be separated by blanks or commas.

Mplus uses a hyphen (-) to indicate a list of variables or numbers. The

use of this feature is discussed in each section for which it is appropriate.

There is also a special keyword ALL which can be used to indicate all

variables. This keyword is discussed with the options that use it.

Following is a set of Mplus input files for a few prototypical examples.

The first example shows the input file for a factor analysis with

covariates (MIMIC model).