The terminology is inconsistent. Alternative names for<unk> ing variables include effect modifiers, predictive factors, or moderators. Alternative names for<unk>  effects include effect modification and interaction. Some authors define effect modification and interaction differently, and distinguish different types of interaction. A more unspecific term is heterogeneity of treatment effects.
Subgroup analysis
Bioprospecting
Sensitivity training
Mixing study
Hypnoanalysis
Platform trial
Parallel study
Intersalt study