# init(validation:batchSize:maxIterations:gridSize:algorithm:) Creates a model parameters instance for an object-detector training session. ``` init(validation: MLObjectDetector.ModelParameters.ValidationData = .split(strategy: .automatic), batchSize: Int? = nil, maxIterations: Int? = nil, gridSize: CGSize = CGSize(width: 13, height: 13), algorithm: MLObjectDetector.ModelParameters.ModelAlgorithmType = .darknetYolo) ``` ## Parameters `validation` An [`MLObjectDetector.ModelParameters.ValidationData`](/documentation/CreateML/MLObjectDetector/ModelParameters-swift.struct/ValidationData) instance that contains your validation dataset. `batchSize` The number of images the object detector uses for each training iteration. If you don’t have a preference, set this parameter to `nil` to tell Create ML to use an appropriate value when it trains the model. `maxIterations` The largest number of training iterations the object detector can use. If you don’t have a preference, set this parameter to `nil` to tell Create ML to use an appropriate value when it trains the model. `gridSize` The number of rectangles, vertically and horizontally, the training algorithm uses to analyze each input image. `algorithm` The algorithm the training session uses to train the object detector. --- Copyright © 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)