Factor analysis is a collection of methods used to examine how underlying constructs influence the responses on a number of measured variables.
There are basically two types of factor analysis: Exploratory and Confirmatory.
Exploratory factor analysis (EFA) attempts to discover the nature of the constructs influencing a set of responses.
Confirmatory factor analysis (CFA) tests whether a specified set of constructs is influencing responses in a predicted way.
The primary objectives of an EFA are to determine:
1. The number of common factors influencing a set of measures.
2. The strength of the relationship between each factor and each observed measure.
Some common uses of EFA are to:
· Identify the nature of the constructs underlying responses in a specific content area.
· Determine what sets of items “hang together" in a questionnaire.
· Demonstrate the dimensionality of a measurement scale. Researchers often wish to develop scales that respond to a single characteristic.
· Determine what features are most important when classifying a group of items.
· Generate “factor scores" representing values of the underlying constructs for use in other analyses.
Steps to perform EFA
There are seven basic steps to performing an EFA:
1. Collect measurements
2. Obtain the correlation matrix
3. Select the number of factors for inclusion
4. Extract your initial set of factors
5. Rotate your factors to a final solution
6. Interpret your factor structure
7. Construct factor scores for further analysis
The primary objective of a CFA is to determine the ability of a predefined factor model to fit an observed set of data.
Some common uses of CFA are to:
· Establish the validity of a single factor model.
· Compare the ability of two different models to account for the same set of data.
· Test the significance of a specific factor loading.
· Test the relationship between two or more factor loadings.
· Test whether a set of factors are correlated or uncorrelated.
· Assess the convergent and discriminant validity of a set of measures.
Steps to perform CFA
There are six basic steps to performing a CFA:
1. Define the factor model
2. Collect measurement
3. Obtain the correlation matrix
4. Fit the model to the data
5. Evaluate model adequacy
6. Compare with other models
POsted by: Yogesh Raisinghani
Operations _ Group 2