Cross entropy loss is crucial in machine learning, particularly in classification problems. It quantifies how well a predicted probability distribution matches the target distribution (the true labels), making it especially useful in training models like neural networks. By minimizing this loss, models can improve their accuracy in predicting outcomes. Cross entropy loss is effective because it penalizes incorrect classifications more heavily when the model is confident about its wrong predictions, accelerating learning and convergence by guiding the model to adjust significant weights.

Historical overview: The concept of cross entropy is derived from information theory, introduced by Claude Shannon in 1948. The use of cross entropy loss in machine learning became prevalent with the rise of deep learning and the need for robust loss functions in the 2000s.

Key contributors: While Claude Shannon laid the foundational work on information theory, the application of cross entropy in machine learning models has been developed and refined by numerous researchers in the field of deep learning, without a single figure being prominently recognized above others. The widespread adoption and adaptation in neural network training algorithms highlight the community-driven advancements in this area.