This is referred to as conservative estimator of ( ) sy Vy by them, but referred to as Systematic Random Estimator (SRE) ( ) SRE Vy in this study, i.e. when ( ) Vy is used to estimate ( ) sy Vy.
This is referred to as conservative estimator of ( ) syVyby them, but referred to as Systematic Random Estimator (SRE) ( ) SREVy in this study, i.e. when ( ) Vy is used to estimate ( ) syVy.