---
title: "MLSoundClassifier.ModelParameters.ModelAlgorithmType.transferLearning(featureExtractor:classifier:)"
framework: createml
role: symbol
role_heading: Case
path: "createml/mlsoundclassifier/modelparameters-swift.struct/modelalgorithmtype/transferlearning(featureextractor:classifier:)"
---

# MLSoundClassifier.ModelParameters.ModelAlgorithmType.transferLearning(featureExtractor:classifier:)

An algorithm that leverages the knowledge of a general-purpose model built into the operating system.

## Declaration

```swift
case transferLearning(featureExtractor: MLSoundClassifier.ModelParameters.FeatureExtractorType, classifier: MLSoundClassifier.ModelParameters.ClassifierType)
```

## Parameters

- `featureExtractor`: The extractor type the algorithm uses to detect features from the audio data.
- `classifier`: The model type the algorithm uses to classify audio data.

## Discussion

Discussion You typically use this transfer-learning algorithm to train an object detector in these situations: Your training dataset has a limited number of examples. You prefer your object detector’s Core ML model file to be as small as possible.

## See Also

### Designating an algorithm

- [MLSoundClassifier.ModelParameters.FeatureExtractorType](createml/mlsoundclassifier/modelparameters-swift.struct/featureextractortype.md)
- [MLSoundClassifier.ModelParameters.ClassifierType](createml/mlsoundclassifier/modelparameters-swift.struct/classifiertype.md)