Title
Counterfactual Estimation and Optimization of Click Metrics for Search Engines.
Abstract
Optimizing an interactive system against a predefined online metric is particularly challenging, when the metric is computed from user feedback such as clicks and payments. The key challenge is the counterfactual nature: in the case of Web search, any change to a component of the search engine may result in a different search result page for the same query, but we normally cannot infer reliably from search log how users would react to the new result page. Consequently, it appears impossible to accurately estimate online metrics that depend on user feedback, unless the new engine is run to serve users and compared with a baseline in an A/B test. This approach, while valid and successful, is unfortunately expensive and time-consuming. In this paper, we propose to address this problem using causal inference techniques, under the contextual-bandit framework. This approach effectively allows one to run (potentially infinitely) many A/B tests offline from search log, making it possible to estimate and optimize online metrics quickly and inexpensively. Focusing on an important component in a commercial search engine, we show how these ideas can be instantiated and applied, and obtain very promising results that suggest the wide applicability of these techniques.
Year
Venue
Field
2014
CoRR
Causal inference,Search engine,Computer science,Counterfactual thinking,Artificial intelligence,Search analytics,Payment,Machine learning
DocType
Volume
Citations 
Journal
abs/1403.1891
6
PageRank 
References 
Authors
0.51
24
4
Name
Order
Citations
PageRank
Lihong Li12390128.53
Shunbao Chen2291.45
Jim Kleban31989.81
Ankur Gupta486055.56