Addressing Vocabulary Gap in E-commerce Search

E-commerce customers express their purchase intents in several ways, some of which may use a different vocabulary than that of the product catalog. For example, the intent for "women maternity gown" is often expressed with the query, "ladies pregnancy dress". Search engines typically suffer from poor performance on such queries because of low overlap between query terms and specifications of the desired products. Past work has referred to these queries as vocabulary gap queries. In our experiments, we show that our technique significantly outperforms strong baselines and also show its real-world effectiveness with an online A/B experiment.