Select an option to orthogonally rotate the initial factor loadings. Minitab rotates the axes to give you a different perspective, which can help you to interpret the factors.
The original factor loadings are often difficult to interpret. Rotation usually creates a simpler factor structure and makes the factors more clearly distinguishable. Rotation also tends to remove general factors that load highly on all variables.
Minitab rotates the loadings to minimize a simplicity criterion. A parameter, gamma (γ), within this criterion, is determined by the rotation method. If you use a method with a low value of gamma, the rotation tends to simplify the rows of the loadings. If you use a method with a high value of gamma, the rotation tends to simplify the columns of the loadings.
- None: Do not rotate the loadings.
- Equimax: Rotate the loadings so that a variable loads high on one factor but low on others. This method is a compromise between the Varimax and Quartimax rotations.
- Varimax: Maximize the squared factor loadings in each factor (gamma = 1). Varimax is the most widely used rotation method. This rotation simplifies the columns of the factor loading matrix. In each factor, the large loadings are increased and the small ones are decreased so that each factor has only a few variables with large loadings.
- Quartimax: Maximize the variance of the squared factor loadings in each variable (gamma = 0). This rotation simplifies the rows of the factor loading matrix. In each variable the large loadings are increased and the small ones are decreased so that each variable will only load on a few factors.
- Orthomax with γ: Use loadings based on the value of gamma that you enter. Enter a gamma value between 0 and 1.
Because you cannot predict whether one type of rotation will make your factors more meaningful, try different rotations. If Equimax, Varimax, and Quartimax do not produce meaningful factors, you can use Orthomax with γ to explore rotations between the varimax rotation (gamma = 1) and the quartimax rotation (gamma = 0).