Reporting populations, denominators, and cohort definitions
A direct method for defining who belongs in a GTM report, what the denominator means, and when a cohort should start and stop being measured.
On this page
“What is our conversion rate?” is unfinished until the team can say conversion of which records, entering when, to which event, and after what exclusions.
Write the population before the metric
Population: people with a first demo request in the period
Entry: form_submitted_at between period start and end
Exclude: test records, duplicates, consent-blocked records
Unit: one person per first request
Follow-up window: 30 calendar daysThis definition prevents a later report filter from changing the question silently.
Denominator checks
| Check | Question |
|---|---|
| Unit | Is the row a person, account, opportunity, run, or event? |
| Entry | Which event starts membership? |
| Dedupe | Can one subject enter twice? |
| Exclusions | Which records cannot be measured fairly? |
| Window | When does the subject have time to complete? |
| Missing | Are incomplete records excluded or counted as unknown? |
Publish the denominator with the metric. A percentage without it is decoration.
Cohorts prevent moving goalposts
For a cohort report, freeze membership at the entry event and measure later outcomes. Do not remove a record because its current status changed. Report the outcome and the reason for missingness separately.
Platform implementation
Build the population as a saved report or view with a named owner and a test record set. Salesforce report types and HubSpot report filters can express many population definitions, though object associations and subscription features differ. Verify the current Salesforce report type documentation and HubSpot report guidance before implementation.
Define time at both ends
State the event that admits a record, the timezone, the measurement window, and the event that closes observation. Decide how to handle reopened records, late-arriving outcomes, duplicate subjects, and records that become ineligible. “Created this quarter” is not enough when the outcome can happen next quarter.
For every rate, write numerator and denominator as record-level tests. Then account for qualified, successful, unsuccessful, still open, excluded, unknown, and bad-data states. These categories should reconcile to the starting population. If they do not, the rate is not ready for a dashboard.
Validate with examples
Keep a small fixture set containing boundary dates, missing values, duplicate associations, a late outcome, and an open record. Ask the metric owner to classify each before running the report, then compare the query result. Monitor population size and exclusion reasons over time; a stable rate on a shrinking denominator can still signal a broken process.
Related: Unknown versus zero versus bad data, GTM metric dictionary template, and Dashboard design and drill-down.
Related guides
FAQ
- What is a reporting denominator?
- The denominator is the defined set of records against which a numerator is compared. It must name the population, entry date, exclusions, and whether each record can count once or more than once.
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