Reconciling two counts
Two reports. Two totals. Before changing a number, find out what each report is actually counting.
A fictional enrollment investigation · About 8 minutes
SDLA’s fictional urban middle school serves 800 students in grades 6–8. Its connected systems still depend on staff to reconcile transfers, schedule changes, and overlapping enrollments.
The school context comes from the SDLA school profiles. All report dates, records, staff actions, and findings below are invented for this learning exercise. These are local enrollment reports, not CALPADS certification results.
Put both reports on the table
Keep the totals attached to their definitions, dates, and sources.
Unique enrolled students
- As of
- November 9, 2026 · end of day
- Generated
- November 10 · 8:00 a.m.
- Scope
- Sierra Vista · grades 6–8
- Count rule
- One student per local ID, actively enrolled on the as-of date
- Excludes
- Future starts and students no longer enrolled on that date
- Source / owner
- SIS enrollment records / school registrar
Unique enrolled students
- As of
- November 6, 2026 · end of day
- Generated
- November 6 · 6:00 p.m.
- Scope
- Sierra Vista · grades 6–8
- Count rule
- One student per local ID, actively enrolled on the as-of date
- Excludes
- Future starts and students no longer enrolled on that date
- Source / owner
- Saved SIS extract / district data analyst
The difference is 3 students. What would you check before calling it an error?
1. Reporting date and refresh time
“As of” tells you which day the records describe. “Generated” tells you when the report was produced. Check both.
2. Population and exclusions
Confirm school, grades, enrollment status, and filters. Similar titles can hide different populations.
3. Unit of record and identifiers
Count unique students, not course enrollments or file rows. Match on approved identifiers, not names alone.
4. Source, transformation, and owner
Trace the source extract, filters, joins, and feed status. Name the person who can explain or correct each step.
Follow an explanation to the evidence
Select a possible cause to see what it would take to establish it.
The reports describe different days
Three students began enrollment on November 9. They belong in the November 9 roster and do not belong in the November 6 snapshot. The exercise assumes no exits or other membership changes between those dates.
| Record | Effective start | Nov. 6 snapshot | Nov. 9 roster |
|---|---|---|---|
| Demo student A | Nov. 9 | Excluded | Included |
| Demo student B | Nov. 9 | Excluded | Included |
| Demo student C | Nov. 9 | Excluded | Included |
Verification: The registrar checks the effective start dates. The analyst reruns the SIS report as of November 6: 797. Both November 6 student-ID sets match, with no unmatched IDs or duplicates.
Resolution: Keep both original totals with their dates. No source correction is needed. Choose the dated population that answers the question being asked.
Matching totals are a starting point. Two reports can both show 797 and still contain different students. Compare the record sets as well as the totals.
How to carry out the record comparison
Preserve both original reports and their parameters. Produce comparable extracts for the same as-of date, school, grades, and enrollment rule. Check that the local student ID is unique at the intended grain before matching records.
List records found only in A, only in B, and in both. Review enrollment dates and status for every unmatched record. Equal counts can hide offsetting differences, so resolve both lists. Have the registrar verify source facts and the analyst verify report logic; rerun affected outputs after an authorized correction.
Leave an explanation someone else can use
Share the finding, the evidence, and the next action together.
The note below starts with the resolved different-dates example. Exploring other explanations does not change your note. Edit it for the exercise, then print or download it. Changes stay in this open page and are lost on reload; download before closing. Keep student-level details in your approved records location.
Reconciliation resolution note
Use the same method locally: preserve the evidence, confirm the explanation, and record who verified it. A selected explanation alone is not proof.
In the print dialog, select your printer or Save as PDF. The note prints your current entries with room for wrapped text.