2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/210262Principal component analysis is considered as an addition to the well-tested parametrization w(a)=w_0+w_a(1-a) for the dark energy equation of state. This brief note cautions against some unjustified assumptions in interpretation of PCA calculations, giving quantified examples.4 pages, 3 figuresAstrophysicstext