Charagram: Embedding Words and Sentences via Character n-grams

John Wieting1, Mohit Bansal2, Kevin Gimpel3, Karen Livescu4
1University of Illinois; TTI-Chicago, 2University of North Carolina at Chapel Hill, 3Toyota Technological Institute at Chicago, 4TTI-Chicago


Abstract

We present Charagram embeddings, a simple approach for learning character-based compositional models to embed textual sequences. A word or sentence is represented using a character n-gram count vector, followed by a single nonlinear transformation to yield a low-dimensional embedding. We use three tasks for evaluation: word similarity, sentence similarity, and part-of-speech tagging. We demonstrate that Charagram embeddings outperform more complex architectures based on character-level recurrent and convolutional neural networks, achieving new state-of-the-art performance on several similarity tasks.