---
title: rootMeanSquaredErrorKey
framework: createml
role: symbol
role_heading: Type Property
path: createml/mlprogress/rootmeansquarederrorkey
---

# rootMeanSquaredErrorKey

They key that accesses the root-mean-squared error value.

## Declaration

```swift
static let rootMeanSquaredErrorKey: ProgressUserInfoKey
```

## See Also

### Accessing error information

- [maximumErrorKey](createml/mlprogress/maximumerrorkey.md)
- [validationMaximumErrorKey](createml/mlprogress/validationmaximumerrorkey.md)
- [validationRootMeanSquaredErrorKey](createml/mlprogress/validationrootmeansquarederrorkey.md)