More Advanced Methods; Factor Analysis Flashcards
________ ______ involves grouping similar variables into dimensions/factors.
Factor analysis
Factor Analysis:
- Most commonly an _________ approach to data analysis.
- Also a _________ manner to data analysis.
- More controversial than other analytic methods leaving room for subjectivity and judgment.
- Crucial multiavariate analysis method to provide structure to data sets with multiple observed variables.
- exploratory (Exploratory Factor Analysis; EFA)
- confirmatory (Confirmatory Factor Analysis; CFA)
EFA is a factor analysis used to do what?
- Explore the possible underlying factor structure of a set of observed variables without imposing a predefined structure of the outcome.
- Identify the underlying factor structure.
- Describe and identify the number of factors.
What are the goals of EFA?
- Determine the number of latent constructs underlying a set of variables.
- Provide a means of explaining variation among variables using only a few newly created factors.
- Define the content of meaning of factors.
What are the underlying assumptions of EFA?
- Continuous level of measurement with normal distribution.
- Sample size should be large enough (more than 200 and 5 observations per variable)
- Correlation >0.3 between the variables.
What are the limitations of EFA?
- Variables could be sample specific, not generalizable.
- Non-normal distribution of data.
- Sample size larger than the required is desirable to accommodate the possible missing data.
- No causal inferences can be made from correlations alone.
CFA is a factor analysis used to do what?
-Test the hypothesis that there exists a relationship between the observed variables and their underlying latent constructs.
What is the 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 or fit indices look up.
What are the limitations of CFA?
- Sample size required to be sufficiently large.
- Multivariate normality.
- Outliers
- Missing data
If unacceptable model fit is found in CFA, an _____ can be performed to identify the underlying structure, describe and identify the number of factors.
EFA
EFA steps?
- ) Developing Factors
- ) Extraction of Factors
- ) Rotation of Factors
- ) Naming Factors
EFA-Developing Factors:
- What does developing factors mean?
- What is Factor Loadings?
- What are the criteria for significance of factor loadings (FL)?
- To examine a large set of behaviors within an individual and categorize them as representing different conceptual elements of the person’s psychological state.
- The coefficient as a measure of the correlation between the individual variable and the overall factor.
- FL >0.3 = minimum consideration
- FL >0.4 = more important
- FL >0.5 = practically significant
EFA-Extraction of Factors: -Example = To study behaviors related to chronic pain in a sample of 150 patients with low back pain. Seven variables are examined and measured on a 5-point Likert scale from 1="never observed" to 5="almost always observed". These seven variables are: 1.) COMPLAINS about pain 2.) CHANGES position frequently while sitting 3.) GROANS, moans, or sighs 4.) RUBS painful body parts 5.) ISOLATES herself or himself 6.) MOVES rigidly and stiffly 7.) Drags feet when WALKING
-With the extraction of factors, pull out only the components with Eigenvalue of at least ___.
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EFA-Rotation of Factors:
-Rotation of factors is a process of developing a unique statistical solution so that each variable relates highly to only ____ factor.
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EFA-Naming Factors:
-Naming Factors is also a process of developing a unique statistical solution so that each variable relates highly to only ____ factor.
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