arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2109.05899cs.LGcs.IRstat.ML
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最优多元排序的在线学习

Online Learning of Optimally Diverse Rankings

KTH Royal Institute of Technology(瑞典皇家理工学院);Spotify AB(Spotify 公司)

Stefan Magureanu, Alexandre Proutiere, Marcus Isaksson, Boxun Zhang

摘要:

搜索引擎通过列出相关项目(例如文档、歌曲、产品、网页等)来回答用户的查询。这些引擎依赖于学习对项目进行排名的算法,以便呈现一个有序列表,最大化它包含相关项目的概率。学习排名算法设计中的主要挑战来自于这样一个事实,即查询对于不同的用户通常具有不同的含义。在没有关于查询的任何上下文信息的情况下,通常必须遵守{ \it多样性}原则,即,返回一个包含查询的各种可能主题或含义的列表。为了形式化这个学习排名问题,我们提出了一个自然的模型,其中(i)项目被分类为主题,(ii)用户发现项目相关,只有当他们匹配的主题,他们的查询,和(iii)引擎是不知道的主题到达查询,也不知道的频率,查询相关的各种主题到达,也不知道的主题相关的点击率的项目。对于这个问题,我们设计了LDR(学习多样性排名),一个算法,有效地学习最佳列表的基础上用户的反馈。我们发现,$T$查询后,遗憾的LDR规模为$O((N-L)\log(T))$其中$N$是所有项目的数量。我们进一步确定,这种缩放无法改进,即,LDR是阶最优的。最后,使用人工和真实世界的数据的数值实验,我们说明了LDR的优越性相比,现有的学习排名算法。

英文摘要:

Search engines answer users' queries by listing relevant items (e.g. documents, songs, products, web pages, ...). These engines rely on algorithms that learn to rank items so as to present an ordered list maximizing the probability that it contains relevant item. The main challenge in the design of learning-to-rank algorithms stems from the fact that queries often have different meanings for different users. In absence of any contextual information about the query, one often has to adhere to the {\it diversity} principle, i.e., to return a list covering the various possible topics or meanings of the query. To formalize this learning-to-rank problem, we propose a natural model where (i) items are categorized into topics, (ii) users find items relevant only if they match the topic of their query, and (iii) the engine is not aware of the topic of an arriving query, nor of the frequency at which queries related to various topics arrive, nor of the topic-dependent click-through-rates of the items. For this problem, we devise LDR (Learning Diverse Rankings), an algorithm that efficiently learns the optimal list based on users' feedback only. We show that after $T$ queries, the regret of LDR scales as $O((N-L)\log(T))$ where $N$ is the number of all items. We further establish that this scaling cannot be improved, i.e., LDR is order optimal. Finally, using numerical experiments on both artificial and real-world data, we illustrate the superiority of LDR compared to existing learning-to-rank algorithms.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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