Check a survey for the selection bias that hides your unhappiest customers

The latest customer satisfaction survey looks great, and only the people who never canceled ever got a chance to see it.

Intermediate to advancedRead 6 minDoing: 30 to 45 minutes once the customer table is open6 steps

▶ Start

What you'll have at the end

A side-by-side comparison of the survey's respondent mix against your full customer base, with the gap named in writing.

Before you start

You need

A survey's response data, plus read access to the same company's customer table, one that records each customer's current status and how long they've been a customer.

Not covered

Estimating what the missing customers would have said, or changing the survey tool's send logic; this recipe only measures and documents who the results actually speak for.

Leans on

6 steps

Where to go next

Write a reproducible data cleaning log

when you want a running log of every judgment call behind the whole cleaned dataset, this caveat included.

Checked 26 Aug 2026

Part of the Data Cleaning and Validation for Analysts cookbook