Segments, Audiences, and Calculated Metrics
Containers decide what is counted
Segments in CJA use three containers: Event, Session, and Person. The container defines what is being counted, so a session-scoped segment filters sessions while a person-scoped segment filters anyone who ever qualified. Sequential segments add then and within logic, which is the only way to express ordering, such as viewing a product then purchasing within seven days. Segments are also the raw material for audiences: publish a segment from CJA to AEP and it becomes an audience that Real-Time CDP can activate to destinations.
Calculated metrics combine metrics with arithmetic and functions such as Sum, Count, and Approximate Count Distinct. They inherit component settings unless you override them, and they carry their own attribution choice, which is where subtle errors appear, because the numerator and denominator can silently use different attribution and lookback.
Traps worth memorizing: a person-scoped segment divided into a session-scoped metric produces a number that is technically valid and business-meaningless. Division by zero returns empty or infinite values, not zero. Audience publication depends on the connection's person ID, refreshes on Adobe's schedule rather than in real time, and segments built on unsupported features cannot be published. Filters placed inside a metric function behave differently from filters applied to the metric.
Rule of thumb: define numerator and denominator with the same scope, attribution, and lookback before you build. Worked example: Conversion Rate equals Orders divided by Sessions, times 100, with both components event-scoped and both using the data view's 30-day attribution; placing Sessions inside the function and Orders outside would misalign them.