Population suppression/eradication: The intention is to reduce or potentially eradicate the target species or population, generally by reducing the fertility in one sex or by biasing sex ratios.
Population modification/replacement: The intention is to replace a wild population with a genetically modified population.
Population modification to enable suppression: There have been proposals to use population modification approaches to render a species susceptible to suppression via another method, for example modifying weeds to render them susceptible to herbicides.
Proof of concept: In some cases the purpose of the research is to demonstrate a gene drive system is feasible in a particular target species. In such cases the eventual intended use in wild populations is not always made clear.