> At the time, its small group of practitioners thought it might be an alternative to the more conventional ANN training algorithm called backpropagation (a for

> At the time, its small group of practitioners thought it might be an alternative to the more conventional ANN training algorithm called backpropagation (a form of stochastic gradient descent). The author doesn't seem to understand what backpropagation is - gradient descent is performed on the derivative formed from backpropagation, they are not forms of one another.