Given an ecommerce query, how well the titles of items for sale match the user intent is an important signal for ranking the items. A well-known technique for computing this signal is to use a standard machine-learned model that uses words as features, targets user clicks and predicts a score to rank the titles. In this paper, we introduce an alternate modeling technique that applies to queries that are frequent enough to have historical click data. For each such query we build a parameterized model of user behavior that learns what makes users skip a title. The parameters are different for each query. Specifically, our model predicts how desirable an item’s title is to the user query by focusing on the worst tokens in the title. The model is learned offline using maximum likelihood based on user behavioral data, significantly improving query processing cost. The model’s output score is used as a feature in a machine learned ranker for e-commerce search at eBay. Besides titles, the model design can easily incorporate any attribute of an item including structured content. In this scope, we present our new title desirability model built for nearly 8M queries recently deployed into the eBay search ecosystem and demonstrate its significant performance improvement over a baseline click-based Na¨ıve Bayes model through different evaluation approaches including A/B testing and human judgment. The reported performance is based on eBay's commercial search engine serving millions of queries each day.
IEEE Big Data, Boston MA, Dec 2017
What is Skipped: Finding Desirable Items in E-Commerce Search by Discovering the Worst Title Tokens
Ishita Khan, Prathyusha Senthil Kumar, Daniel Miranda, David Goldberg