Neural Network Calibration


Created: =dateformat(this.file.ctime,"dd MMM yyyy, hh:mm a") | Modified: =dateformat(this.file.mtime,"dd MMM yyyy, hh:mm a") Tags: knowledge


Papers

Introduction

  • DNNs are highly successful in computer vision tasks.

  • While accuracy is a focus, the reliability of confidence scores (uncertainty) is equally important.

  • DNNs often overestimate confidence scores, making them unreliable.

    • For instance, if a DNN assigns a confidence score of 0.8 to a set of predictions, it should be correct 80% of the time.
  • Accurate calibration of uncertainty is crucial for real-world applications.

    Transclude of Neural-Network-Calibration-2023-10-26-15.40.09.excalidraw

  • Confidence calibration refers to the capacity of a model to furnish accurate probability estimates for its predictions.

    • In simpler terms, when a neural network assigns a confidence level of 0.2 to an image being a cat, this confidence score should accurately reflect a 20% likelihood of the prediction being correct, provided that the neural network is appropriately calibrated.
  • By associating each prediction with a calibrated probability score, it becomes possible to identify and discard low-quality predictions.

  • Consequently, even if we don’t have a complete understanding of the neural network’s inner workings, confidence calibration offers a practical method for averting significant errors in real-world scenarios by providing accurate uncertainty assessments for each prediction.

SoftMax Score and Model Confidence

  • Practitioners often erroneously interpret predictive probabilities obtained from a neural network (i.e., the SoftMax scores) as model confidence. However, it is widely known that modern neural networks often make poor (i.e., incorrect) predictions with SoftMax scores of nearly 100%, making predictive probability a poor and misleading estimate of true confidence.

Questions

  • what about underconfidence?