Before revision:  Classification-based approaches work well for small numbers of candidate authors, but only similarity-based methods  are applicable for larger numbers of authors or for authors beyond the training set . While deep learning methodshave been applied to classification-based approaches, applications to similarity-based applications have been limited, and most similarity-based methods only embody static notions of similarity .
After revision:  Classification-based approaches work well for small numbers of candidate authors, but only similarity-based methods are applicable for larger numbers of authors or for authors beyond the training set ; these existing similarity-based applications have been limited, and most similarity-based methods only embody static notions of similarity .