It may be a good idea to limit possible interpretations of OOV words on the basis of the shape. For example, given word x with shape sh(x), limit the set of x's possible interpretations to a set of tags assigned to words in the training corpus with shape sh(x).
It may be a good idea to limit possible interpretations of OOV words on the basis of the shape. For example, given word x with shape sh(x), limit the set of x's possible interpretations to a set of tags assigned to words in the training corpus with shape sh(x).