> ## Documentation Index
> Fetch the complete documentation index at: https://docs.citino.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Within noise

> Why some changes are shown muted with no arrow, and why they never raise an alert.

> How much this moved since the previous period of the same length, in percentage points. “Within noise” means the move is smaller than the ± range, so it could be chance.

AI engines do not give the same answer twice. Some movement from one period to the next is just that, and Citino will not dress it up as a trend.

## How a change is shown

* **In points.** A change is the difference between two percentages, in percentage points (`pts`), never the percentage increase on the first figure.
* **Against the previous period of the same length.** On the 30-day window, the last 30 days are compared with the 30 days before them.
* **New questions are left out of the comparison.** A question that was not yet running in the earlier period is left out of both sides, so adding questions does not look like a jump.

Then one rule decides how it looks:

| The change is | You see |
| - | - |
| Larger than its `±` range | The change in points, with an up or down arrow and colour. |
| Smaller than its `±` range | The change, muted, labelled **within noise**, with no arrow and no colour. |

If a number has no `±` range to compare with, any change in it is treated as within noise. Not knowing how wide the uncertainty is counts as "not news".

## What "within noise" stays out of

A change within noise is never treated as a move anywhere in the product:

* **The digest.** Overview's what-moved list shows "Only the changes big enough to be real rather than chance. If nothing is listed, nothing moved by more than its ± range."
* **Alerts.** "A change small enough to be chance never raises an alert."
* **Sorting.** It never sorts as a movement.

## What to do with a change within noise

* **Do not report it as a win or a loss.** It may well be real, but the data cannot tell it from chance yet.
* **Look at a longer window.** More answers usually narrow the range.
* **Check the `±` itself.** The range is worked out across your questions, so when there are few of them, adding questions narrows it as well as waiting does. See [The ± band and n](https://docs.citino.ai/guides/bands-and-sample-size.md).

## Related

> [card] [The ± band and n](https://docs.citino.ai/guides/bands-and-sample-size.md)
>
> Where the range comes from.

> [card] [Drift labels](https://docs.citino.ai/guides/drift-labels.md)
>
> When the whole engine moves at once.

> [card] [Alerts](https://docs.citino.ai/guides/screens/alerts.md)
>
> What does raise an alert.

> [card] [How bands are computed](https://docs.citino.ai/guides/methodology/bands.md)
>
> The method behind the range.


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