10,323 research outputs found
Incorporating Clicks, Attention and Satisfaction into a Search Engine Result Page Evaluation Model
Modern search engine result pages often provide immediate value to users and
organize information in such a way that it is easy to navigate. The core
ranking function contributes to this and so do result snippets, smart
organization of result blocks and extensive use of one-box answers or side
panels. While they are useful to the user and help search engines to stand out,
such features present two big challenges for evaluation. First, the presence of
such elements on a search engine result page (SERP) may lead to the absence of
clicks, which is, however, not related to dissatisfaction, so-called "good
abandonments." Second, the non-linear layout and visual difference of SERP
items may lead to non-trivial patterns of user attention, which is not captured
by existing evaluation metrics.
In this paper we propose a model of user behavior on a SERP that jointly
captures click behavior, user attention and satisfaction, the CAS model, and
demonstrate that it gives more accurate predictions of user actions and
self-reported satisfaction than existing models based on clicks alone. We use
the CAS model to build a novel evaluation metric that can be applied to
non-linear SERP layouts and that can account for the utility that users obtain
directly on a SERP. We demonstrate that this metric shows better agreement with
user-reported satisfaction than conventional evaluation metrics.Comment: CIKM2016, Proceedings of the 25th ACM International Conference on
Information and Knowledge Management. 201
Counterfactual Estimation and Optimization of Click Metrics for Search Engines
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
Improving Search through A3C Reinforcement Learning based Conversational Agent
We develop a reinforcement learning based search assistant which can assist
users through a set of actions and sequence of interactions to enable them
realize their intent. Our approach caters to subjective search where the user
is seeking digital assets such as images which is fundamentally different from
the tasks which have objective and limited search modalities. Labeled
conversational data is generally not available in such search tasks and
training the agent through human interactions can be time consuming. We propose
a stochastic virtual user which impersonates a real user and can be used to
sample user behavior efficiently to train the agent which accelerates the
bootstrapping of the agent. We develop A3C algorithm based context preserving
architecture which enables the agent to provide contextual assistance to the
user. We compare the A3C agent with Q-learning and evaluate its performance on
average rewards and state values it obtains with the virtual user in validation
episodes. Our experiments show that the agent learns to achieve higher rewards
and better states.Comment: 17 pages, 7 figure
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