The objective function is then expressed as follows: That is, the goal is to set the model parameters in a way that maximizes the probability of all observations coming from the training data.
assume now that D is a set of randomly selected incorrect (c , t ) pairs that do not occur in D, then Equation 2 above can be recasted in the following way: (3) the model tries to distinguish a target word t from random draws that come from a noise distribution.