WooCommerce Post-Purchase Survey: 7 Questions, When to Ask and What to Do Next Survey data cleaning calculator
Calculate how many valid responses remain after removing low-quality surveys: speeders, duplicates, straight-lining and incomplete interviews.
Responses and exclusions
All completed or received surveys
Completed unrealistically fast
Identical answers across matrix rows
Repeat responses from the same person
Other exclusions
Interpretation
Change the inputs to recalculate.
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How the clean sample is calculated
Formula
Valid responses = total responses − excluded responses. Removal rate = excluded / total × 100%.
Speeders
Finishing too fast often means low attention to the questions.
Straight-lining
Identical answers in grids can be genuine but need checking in context.
Removal rate
A high share of exclusions points to problems with the channel or the questionnaire.
Calculation examples
1 Customer survey
2 Panel fieldwork
What to avoid
- Removing without rules Fix the cleaning criteria in advance, otherwise it is easy to distort the result.
- Treating every straight-liner as bad Someone who genuinely rates all items the same is not necessarily a low-quality respondent.
- Not recording why responses were removed Keep the exclusion categories and their shares for a transparent report.
Frequently asked questions
What removal rate is normal?
What counts as speeding?
How do I set the minimum time?
Should I remove incomplete responses?
How can I reduce bad data?
Automate your metrics
In SurveyNinja, NPS, CSAT and more are calculated automatically. Create a survey in 5 minutes and get real-time analytics.
Start free