Autodiff

Automatic differentiation, often called autodiff, is a computational technique that plays a significant role in AI, particularly in training neural networks within ML frameworks. Unlike symbolic differentiation, which can become excessively complex, or numerical differentiation, which suffers from approximation errors, autodiff provides an exact and efficient way to compute derivatives through the systematic application of the chain rule at a computational level. This method underlies the optimization algorithms used in deep learning by automating the gradient calculation process, thus enabling efficient backpropagation for neural network training. Autodiff implementations are deeply embedded in popular AI libraries, such as TensorFlow and PyTorch, providing the foundational capabilities for gradient-based optimization methods across vast and complex AI models.

Automatic differentiation came into use in the 1960s with early computational studies but gained significant attention and adoption in the AI community around the 1980s when differentiable programming began supporting gradient-based learning in neural networks, setting the stage for modern deep learning techniques.

Key contributors to the development of autodiff include Andreas Griewank and Andrea Walther, who have extensively researched and formalized techniques in the autodiff field, while additional significant expansions were made by developers of major AI frameworks such as the Google Brain team and Facebook AI Research, which further popularized it through practical implementations in TensorFlow and PyTorch, respectively.