IBM SPSS Amos
Structural Equation Modelling (SEM) provides a unifying framework under which numerous linear models may be fit using flexible, powerful software.
What is SPSS Amos?
Amos stands for Analysis of a Moment Structures.
SPSS Amos is structural equation modelling software that enables users to specify, estimate, assess and present models to show hypothesized relationships among variables for attitudinal and behavioural models that reflect complex relationship (such as confirmatory factor analysis and time series analyses) more accurately than with standard multivariate statistic techniques. Amos is an independent software package used to build graphical data models or non-graphical, programmatic interface.
The basic approach to performing a SEM analysis is as follows:
The researcher first specifies a model based on theory, then determines how to measure constructs, collects data, and then inputs the data into the SEM software package. The package fits the data to the specified model and produces the results, which include overall model fit statistics and parameter estimates.
The input to the analysis is usually a covariance matrix of measured variables such as survey item scores, though sometimes matrices of correlations or matrices of covariance and means are used. In practice, the data analyst usually supplies SEM programs with raw data, and the programs convert these data into covariance and means for its own use.
The model consists of a set of relationships among the measured variables. These relationships are then expressed as restrictions on the total set of possible relationships.
The results feature overall indexes of model fit as well as parameter estimates, standard errors, and test statistics for each free parameter in the model.
Researchers choose Structural Equation Modelling because of a number of attractive virtues:
- Assumptions underlying the statistical analyses are clear and testable, giving the investigator full control and potentially furthering understanding of the analyses.
- Graphical interface software boosts creativity and facilitates rapid model debugging (a feature limited to selected Structural Equation Modelling software packages).
- Structural Equation Modelling (SEM) programs provide overall tests of model fit and individual parameter estimate tests simultaneously.
- Regression coefficients, means, and variances may be compared simultaneously, even across multiple between-subjects groups.
- Measurement and confirmatory factor analysis models can be used to purge errors, making estimated relationships among latent variables less contaminated by measurement error.
- Ability to fit non-standard models, including flexible handling of longitudinal data, databases with auto correlated error structures (time series analysis), and databases with non-normally distributed variables and incomplete data.
- Structural Equation Modelling (SEM) provides a unifying framework under which numerous linear models may be fit using flexible, powerful software.
What can SPSS Amos do?
- Create graphical data models of analysis by using drawing tools instead of writing equations or typing commands.
- Compare, confirm, refine and choose model from number of candidates by using equation model specification search.
- Non-graphical modelling for programmers and non-programmers to specify a structural equation models without drawing a path diagram.
- Amos path diagram shows strength of relationship between variables.
- Extends standard multivariate analysis methods, including regression, factor analysis, correlation, and analysis of variance.
What type of files are associated with SPSS Amos
*amw – An Amos model file which contains the model diagram.
Who typically uses IBM SPSS Amos?
SPSS Amos is used for teaching and research purposes most of the time. SPSS Amos is only compatible with Windows and can be installed on any university-owned computers.
Faculty and Academic staff wishing to purchase Amos may purchase an educational license through www.olspsanalytics.com
To start using SPSS Amos most of the users attend SPSS Amos training at OLSPS Analytics, where delegates learn: Introduction to SEM, Regression with SPSS Amos, Testing model adequacy, Principles of testing applied, The general model, Special topics.
Requirements to SPSS Amos users: Any user of SPSS Amos must have basic knowledge of factor analysis, and some experience in multiple regression