Glossary
Completion rate vs conversion rate
Finishers among starters versus submissions among all viewers.
These two metrics measure different things and are routinely confused. Conversion rate is submissions divided by everyone who viewed the form. Completion rate is submissions divided by everyone who started it. One judges the whole funnel; the other judges only the form's internal experience.
The distinction is diagnostic. A healthy completion rate with a poor conversion rate means people are not starting — the headline, length signal, or context is the problem, not the questions. A poor completion rate means mid-form friction, and per-question drop-off will point to the field.
Always report both. Optimising conversion by, say, hiding the form length can lift starts while tanking completion as people hit unexpected questions and abandon. Watching the pair together prevents that kind of false win.