# How decodx measures visibility

> How decodx counts answer checks, and why past numbers can change.

:::info[Short answer]

Answer engines give a different answer each time. decodx asks each question more than once, in each region and for each persona that you select. decodx reports the average of all answers.

:::

## Answer checks in one run

```text
answer checks = questions × engines × samples × regions × personas
```

## Why past numbers can change

- You add or remove a competitor.
- You change the questions.
- An answer engine changes its model or its sources.

## AI referrals

Connect Google Analytics 4. decodx then counts the visits that come from AI answers to your site.