<!--
{
  "availability" : [
    "macOS: 10.15.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "CreateML",
  "identifier" : "/documentation/CreateML/MLRecommender/SimilarityType",
  "metadataVersion" : "0.1.0",
  "role" : "Enumeration",
  "symbol" : {
    "kind" : "Enumeration",
    "modules" : [
      "Create ML",
      "CreateML"
    ],
    "preciseIdentifier" : "s:8CreateML13MLRecommenderV14SimilarityTypeO"
  },
  "title" : "MLRecommender.SimilarityType"
}
-->

# MLRecommender.SimilarityType

The metric by which the recommender computes item similarity.

```
enum SimilarityType
```

## Topics

### Similarity types

[`case jaccard`](/documentation/CreateML/MLRecommender/SimilarityType/jaccard)

The Jaccard similarity measure.

[`case cosine`](/documentation/CreateML/MLRecommender/SimilarityType/cosine)

The cosine similarity measure.

[`case pearson`](/documentation/CreateML/MLRecommender/SimilarityType/pearson)

The Pearson correlation similarity measure.

### Similarity type descriptions

[`var description: String`](/documentation/CreateML/MLRecommender/SimilarityType/description)

A text representation of the similarity type.

[`var debugDescription: String`](/documentation/CreateML/MLRecommender/SimilarityType/debugDescription)

A text representation of the similarity type that’s suitable for output during debugging.

[`var playgroundDescription: Any`](/documentation/CreateML/MLRecommender/SimilarityType/playgroundDescription)

A description of the similarity type shown in a playground.

### Default Implementations

[CustomDebugStringConvertible Implementations](/documentation/CreateML/MLRecommender/SimilarityType/CustomDebugStringConvertible-Implementations)

[CustomPlaygroundDisplayConvertible Implementations](/documentation/CreateML/MLRecommender/SimilarityType/CustomPlaygroundDisplayConvertible-Implementations)

[CustomStringConvertible Implementations](/documentation/CreateML/MLRecommender/SimilarityType/CustomStringConvertible-Implementations)

## Relationships

### Conforms To

[`SendableMetatype`](/documentation/Swift/SendableMetatype)

[`Copyable`](/documentation/Swift/Copyable)

[`CustomPlaygroundDisplayConvertible`](/documentation/Swift/CustomPlaygroundDisplayConvertible)

[`Equatable`](/documentation/Swift/Equatable)

[`CustomStringConvertible`](/documentation/Swift/CustomStringConvertible)

[`Escapable`](/documentation/Swift/Escapable)

[`CustomDebugStringConvertible`](/documentation/Swift/CustomDebugStringConvertible)

[`Sendable`](/documentation/Swift/Sendable)

[`Hashable`](/documentation/Swift/Hashable)

---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)