There's also the more challenging problem of zero-shot learning, e.g.: http://jmlr.org/proceedings/papers/v37/romera-paredes15.pdf http://jmlr.org/proceedings/

There's also the more challenging problem of zero-shot learning, e.g.: http://jmlr.org/proceedings/papers/v37/romera-paredes15.pdf http://jmlr.org/proceedings/papers/v37/romera-paredes15.pdf "Zero-shot learning consists in learning how to recognise new concepts by just having a description of them."