  We explore snares in determining the equation of state of dark energy
($\omega$) when one uses the so-called principal component analysis for
multiple observations. We demonstrated drawbacks of principal component
analysis in an earlier paper. We used the Hubble parameter data generated from
a fiducial model using the so-called Chevallier-Polarski-Linder
parameterization. We extend our previous consideration to multiple
observations, the Hubble parameter and the luminosity distance. We find that
the principal component analysis produces the almost constant $\omega$ even
when a fiducial model is a rapidly varying $\omega$. Thus, resolution of
dynamical property of $\omega$ through PCA is degraded especially when one fits
to several observations.
