Multi-space probabilistic sequence modeling

Shuo Chen, Jiexun Xu, Thorsten Joachims

Abstract: Learning algorithms that embed objects into Euclidean space have become the methods of choice for a wide range of problems, ranging from recommendation and image search to playlist prediction and language modeling. Probabilistic embedding methods provide elegant approaches to these problems, but can be expensive to train and store as a large monolithic model. In this paper, we propose a method that trains not one monolithic model, but multiple local embeddings for a class of pairwise conditional models especially suited for sequence and co-occurrence modeling. We show that computation and memory for training these multi-space models can be efficiently parallelized over many nodes of a cluster. Focusing on sequence modeling for music playlists, we show that the method substantially speeds up training while maintaining high model quality.