# Survey participation and completion denominators

Distinguish invited people, started questionnaires and completed questionnaires before reporting a survey participation percentage.

If nothing was unclear or difficult, say so. Skip questions about steps you did not experience; use not applicable where appropriate.

## 1. What experience does this invitation ask you to have had?

Answer: ____________________

## 2. Which part of the invitation explains why you were contacted?

Answer: ____________________

## 3. What would help you decide whether to start the questionnaire?

Answer: ____________________

## 4. Which instruction is unclear if you begin but cannot finish?

Answer: ____________________

## Author notes / illustrative keys where applicable

1. Check whether the stated experience matches the intended invitation cohort.
2. Find ambiguity in eligibility rather than interpreting nonparticipation as disinterest.
3. Separate unclear purpose from missing access or time.
4. Clarify the partial-completion route without pressuring people to finish.

Interpretation caution: This invited-cohort calculation is not a formal AAPOR response-rate estimate. Unknown eligibility, duplicate invitations and partial cases require an explicit disposition policy.


## Illustrative finding and follow-up

Observation: Synthetic cohort: 40 eligible people invited, 20 started and 12 finished. One draft uses 40 as its denominator; another uses 20.

Action to test: Report 12/40 invited-cohort participation and 12/20 started-questionnaire completion separately; document who entered each count.

Follow-up: Reconcile the next cohort’s invitation, start and finish counts using the same definitions; inspect why eligible people could not participate.


## Collection protocol

When and whom to ask: Pilot with a few people who fit the invitation rule before sending the full questionnaire; participation is optional.

Decision owner: The survey owner defines eligibility and distinct invitations; the reporting reviewer checks all three counts.

Follow-up: After clarifying the invitation, review participation barriers under the same inclusion rule; do not attribute a changed percentage to wording alone.

Response handling: Keep contact details out of this worksheet. Explain whether pilot comments can be linked to an invitation record; accept a skip without repeated pressure.


## Worked measurement study

All example records are synthetic; manual worksheet, no automatic import.

### Inspect the synthetic example

Known-cohort count | People
--- | ---
Eligible invited people | 40
Distinct starters | 20
Distinct finishers | 12

### Derivation

Invited-cohort participation = 12÷40×100 = 30%. Completion among starters = 12÷20×100 = 60%. Both use 12 finishers but answer different questions.

Reporting note: 30% of the known eligible invitation cohort finished; 60% of starters finished. This is descriptive cohort reporting, not a formal response-rate or representativeness claim.

Calculator inputs and convention: {"mode": "ratio", "labels": ["Distinct finishers", "Eligible invited people"], "values": [12, 40], "unit": "% invited-cohort participation", "integer": true, "subset": true}

### Evidence boundary

Observed / Known invitation, start and finish counts / Supports two labelled percentages.
Unknown / Views of people who did not respond / Do not infer satisfaction or population coverage.
Next check / Inspect eligibility and duplicate-invitation policy / Resolve the denominator before comparing campaigns.

### Method references

AAPOR response rate resources: https://aapor.org/response-rates/ — Formal response-rate terminology requires an appropriate disposition definition.