We also came to the conclusion that they are not the kind of words we want to have in the cache, since their presence in a sentence implies little about their presence in the next.
the resulting model is of the form: every f cache sw has a corresponding weight γ sw for the calculation of the probability of w.   We implemented two versions of the model, one in which we estimated only one cache feature weight for the whole model and another in which we estimated one cache feature weight for every word pair in the model.