2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/212073In this paper we introduce an influence measure based on second order expansion of the RV and GCD measures for the comparison between unperturbed and perturbed eigenvectors of a symmetric matrix estimator. Example estimators are considered to highlight how this measure compliments recent influence analysis. Importantly, we also show how a sample based version of this measure can be used to accurately and efficiently detect influential observations in practice.Published in at http://dx.doi.org/10.1214/08-EJS201 the Electronic Journal of Statistics (http://www.i-journals.org/ejs/) by the Institute of Mathematical Statistics (http://www.imstat.org)Statistics Theory62F35 (Primary) 62H12 (Secondary)text