covary

verb

1. To vary together with another variable, particularly in a way that may be predictive

   “More specifically, to say that there is an informative criterion of diachronic identity is to say that facts of diachronic identity covary with facts about continuants’ instantaneous qualitative profiles […].”

   “The participants certainly differ in how their practice is distributed (1, 2, or 3 days), but they also differ in how much total practice they get (3, 6, or 9 hours). This is a perfect example of a confound—it is impossible to tell if the results are due to one factor (distribution of practice) or the other (total practice hours); the two factors covary perfectly.”