Modeling with latent variables
There are three common ways of modeling data using the
latent variables approach:
- Principal component regression (PCR ) which generates the
latent variables from the independent variables X. Selected latent variables are then used to fit the dependent variables by multiple linear regression. PCR
calculations can be based on the singular value decomposition (SVD) of the
matrix X'X.
- Maximum redundancy analysis (MRA) generates the
latent variables from the dependent variables Y. This
approach seeks directions in the factor space with the most variation in the
dependent (response) variables. Predictive results are often not very
accurate. MRA calculations are based on the SVD of the matrix
Y'Y.
- Partial least squares regression (PLS)
attempts to set up a model using two sets of latent variables, one set is
based on the independent variables X, the other is calculated
from the dependent variables Y. The PLS approach usually
yields the best results of these three methods. PLS calculations can
be based on the SVD of the matrix X'Y.
|