Factor Analysis Flashcards
How is Factor Analysis most commonly used
an exploratory approach:
- good to examine the structure within a large number of variables
- good to explain the nature of their relationships
How is Factor Analysis used in a confirmatory manner
- used to verify the factor structure of a set of observed variables
- used to test the hypothesis that a relationship between observed variables and their underlying latent constructs exists
Exploratory Factor Analysis is used to:
- Explore possible underlying factor structure of a set of observed variables without imposing a predefined structure to the outcome
- Identify the underlying factor structure
- Describe and ID the # of factors
Goals to EFA
determine the # of latent constructs underlying a set of variables
provide a means of explaining variation among variables using few new factors
define the content of meaning of factors
Assumptions of EFA
continuous level of measurement with normal distribution
sample size should be large enough
correlation >0.3 between the variables
Limitations of EFA
variables could be specific
non-normal distribution of data
sample size larger than required is desirable to accommodate for possible missing data
No casual interferences can be made from correlations alone
Confirmatory Factor Analysis is used to:
Test the hypothesis that there exists a relationship between the observed variables and their underlying latent constructs
Procedure of CFA
- review the relevant theory and research literature to support model specification
- specify a model
- collect data
- assess model fit by
- hypothesis testing
- fit indices look up
Limitations of CFA
sample size must be large
multivariate normality
outliers
missing data
Exploratory Factor Analysis:
Factor Loadings
the coefficient as a measure of the correlation between the individual variable and the overall factor
Exploratory Factor Analysis:
Criteria for significance of Factor Loadings
FL>0.3: minimum consideration
FL>0.4: more important
FL>0.5: practically significant
Exploratory Factor Analysis:
Extraction of Factors
Pull out only the components using a cutoff point where eigenvalue at least 1
Exploratory Factor Analysis:
Rotation of Factors
Process of developing a unique statistical solution so that each variable relates highly to only one factor
Exploratory Factor Analysis:
Naming Factors
Naming the factors assigned in Rotation of Factors
Applications of Factor Analysis
Exploratory Analysis Reduction of data Factor scores Construct Validity Hypothesis Testing