Comparisons
Pairs that get conflated in real conversations. Neither column wins — what decides is the situation. Each record leads with the confusion, because the confusion is the reason the record exists.
Outcome vs outputFirst version vs prototypeDecision record vs one-pagerSuccess metric vs guardrailReversible vs irreversible decisionsFeature flag vs long-lived branchNumbers vs conversationsIncident vs bug
Numbers vs conversations
What people get wrong about this pair
Teams with a dashboard stop talking to users; teams without one ship on anecdotes. A number without a story gets misread, and a story without a number gets over-weighted because it was vivid. Five conversations explain the chart; the chart says whether the five were typical.
Quantitative signals
Use it when
To know *whether* something is happening and how much.
Qualitative signals
Use it when
To know *why* — and to find the thing you did not think to measure.
| Aspect | Quantitative signals | Qualitative signals |
|---|---|---|
| Answers | How many, how often, how much | Why, and what else |
| Cost | Instrumentation up front | Time, and the discipline to listen |
| Fails when | You measured the wrong thing | You talked to the wrong five people |
| Best use | Deciding whether to invest more | Deciding what to build next |