Which student event is being counted?
Digital Rocket's enrollment cohort method follows a declared intake window from inquiry to application, accepted offer, enrolled student, and started or attended student, while keeping each denominator visible.
| Stage | Required record | Common counting error |
|---|---|---|
| Inquiry | Unique attributable person in the declared window. | Counting duplicate forms or existing students. |
| Application | Submitted application that meets the provider's completion rule. | Counting a started but abandoned form. |
| Accepted | Offer or acceptance recorded under the provider's policy. | Assuming acceptance equals enrollment. |
| Enrolled | Enrollment event and payment status defined in advance. | Mixing deposits, reservations, and completed enrollments. |
| Started / attended | Declared attendance or course-start record. | Treating an enrollment as a filled seat after cancellation. |
How to read a cohort without hiding lag.
- Choose one intake or course-start cohort and freeze its observation date.
- Deduplicate people before computing any stage rate.
- Assign media, agency, creative, and declared tracking costs to the same period.
- Separate enrolled and started denominators; show cancellations, refunds, deferrals, and waitlist movement.
- Report open records as open rather than forcing them into won or lost.
Cost per enrolled student equals included acquisition cost divided by attributed enrolled students under the stated rule. Cost per started student uses the started or attended denominator instead. Neither label is complete without the time window and inclusions.
Which economics belong in the model?
Inclusions
Media, management, declared creative and tracking cost, enrollments, starts, capacity, cancellations, refunds, tuition collected, and variable delivery cost.
Exclusions
Unattributed organic records unless separated, duplicate people, unpaid reservations outside the definition, invented tuition, and cross-cohort revenue.
Geography: keep tuition, funding, delivery, tax, and refund assumptions in the provider's own market and currency. Do not merge unlike programs solely to produce a larger denominator.
What the arithmetic looks like.
| Input | Invented value | Purpose |
|---|---|---|
| Included acquisition cost | 12,000 currency units | Numerator |
| Enrolled students | 24 | Enrollment denominator |
| Started students | 20 | Start denominator |
| Illustrative CPE / start cost | 500 / 600 | Ratio arithmetic only |
Replace every value with provider-owned records. A lower ratio is not automatically better if capacity, margin, attendance, or student fit worsens.
What this method cannot answer alone.
- It does not prove an ad caused an enrollment.
- It does not measure teaching quality, educational outcomes, or regulatory compliance.
- Late cancellations and deferrals can materially change an immature cohort.
- Different programs require separate contribution-margin and capacity inputs.
Research governance.
- Author
- Ivan Janku, founder, Digital Rocket
- Reviewer
- Digital Rocket editorial desk
- Review date
- July 13, 2026
- Corrections
- Submit a definition or arithmetic correction through the contact route.
- Owner
- Digital Rocket vocational measurement desk
- Evidence
- Source and proof ledger