HSS is a methodological tool of sampling for qualitative inquiry.HSS is inevitably related to Equifinality Point (EFP) as a research focus. Researchers set their spontaneous interesting research focus by themselves (neither obeying professor's instruction nor reading antecedent references). Then HSS makes it possible to pick up participants who experienced an Equifinality point while arriving there through very different life course trajectories (neither random sampled people nor college students).