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  • 7/31/2019 Sem Chapter 1.5

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    12 | Introduction of Structural Equation Modeling 2012

    1.5 SUMMARY

    In this chapter we introduced structural equation modeling by describing ebasic types of

    variableslatent, observed, independent, and dependentand basic types of SEM models

    regression, path, confirmatory factor, and structural equation models. In addition, we gave a brief

    history of structural equation modeling and a discussion of the importance of SEM. The chapter

    concluded with information about where to obtain the structural equation modeling software

    programs used in the book. In chapter 2 we consider the importance of examining data for issues

    related to measurement level (nominal, ordinal, interval, or ratio), restriction of range (fewer than

    15 categories), missing data, outliers (extreme values), linearity or nonlinearity, and normality or

    nonnormality, which affect all statistical methods, and especially SEM applications.

    EXERCISES

    1. Define the following terms:

    a. Latent variable

    Latent variable: an unobserved variable that is not directly measured, but is computed usingmultiple observed variables.

    b. Observed variable

    Observed variable: a raw score obtained from a test or measurement instrument on a trait ofinterest.

    c. Dependent variable

    Dependent variable: a variable that is measured and related to outcomes, performance orcriterion.

    d. Independent variable

    Independent variable: a variable that defines mutually exclusive categories (e.g., gender, region,

    or grade level) or, as a continuous variable, influences a dependent variable.

    2. Explain the difference

    2. Explain the difference between a dependent latent variable and a dependent observed variable.

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    13 | Introduction of Structural Equation Modeling 2012

    A dependent latent variable is not directly measured, but is computed using multiple dependent

    observed variables. A dependent observed variable is a raw score obtained from a measurementinstrument or assigned to a criterion variable.

    3. Explain the difference between an independent latent variable and an independent observed

    variable.

    An independent latent variable is not directly measured, but is computed using multiple

    independent observed variables. An independent observed variable is a raw score obtained froma measurement instrument or assigned to an attribute variable.

    4. List the reasons why a researcher would conduct structural equation modeling.

    a. Researchers are becoming more aware of the need to use multiple observed variables tobetter understand their area of scientific inquiry.

    b. More recognition is given to the validity and reliability of observed scores frommeasurement instruments.c. Structural equation modeling has improved recently, especially the ability to analyzemore advanced statistical models.

    d. SEM software programs have become increasingly user-friendly5. Download the student versions of Amos, EQS, and LISREL from the websites given in thischapter.

    a. Amos: http://www.smallwaters.com/

    b. EQS: http://www.mvsoft.com/c. LISREL: http://www.ssicentral.com/