Glossary
Progressive disclosure
Revealing complexity only as a respondent needs it.
Progressive disclosure is the design principle of showing the minimum a respondent needs right now, and surfacing additional fields only when their context calls for them. A short core form expands just for the people whose answers require detail.
It is the design intent that conditional logic and multi-page forms implement. The logic is the mechanism; progressive disclosure is the reason — keep the default path short, and let depth appear on demand rather than up front.
Applied well it lowers perceived effort and abandonment without sacrificing data richness: simple cases stay simple, complex cases still get captured. Applied poorly — fields popping in and out as the user types — it feels unstable, so reveal at deliberate moments like a choice selection or a page transition.