Updating mean and variance estimates an improved method
Linear MMSE estimators are a popular choice since they are easy to use, calculate, and very versatile.
In simpler terms, IQ goes from being weakly correlated with genetics, for children, to being strongly correlated with genetics for late teens and adults.
In such case, the MMSE estimator is given by the posterior mean of the parameter to be estimated.
Since the posterior mean is cumbersome to calculate, the form of the MMSE estimator is usually constrained to be within a certain class of functions.
In a similar way, up to now we've focused on understanding the backpropagation algorithm.
It's our "basic swing", the foundation for learning in most work on neural networks.