Task Based Information Retrieval

搜索的需求通常源于人们实现目标或完成任务的需要，如预订旅行、购买房子等。当前的搜索引擎专注于检索与提交的查询相关的文档，而不是理解和支持导致用户提交查询的底层信息需求（或任务）。因此，搜索引擎用户往往要向当前系统提交多个查询才能实现单一的信息需求。在认识到用户经常需要重新表述他们的查询以实现他们的最终目标之后，大多数当前的搜索引擎都试图通过向用户建议查询来帮助他们更好地表达他们的需求，而不是当前发出的查询。然而，查询建议主要侧重于帮助用户改进他们当前的查询，而不是帮助他们识别和探索与其当前复杂任务相关的方面。例如，当用户发出“飞往巴塞罗那的航班”查询时，很明显用户计划前往巴塞罗那，并且很可能用户还需要搜索巴塞罗那的酒店或巴塞罗那机场的班车。由于查询建议主要是针对当前查询的细化，所以常用搜索引擎提供的建议多为“flights to Barcelona from LOCATION”或“FLIGHT-CAREER-NAME flights to Barcelona”的形式，这些系统提供的结果页面中没有任何可以帮助用户预订酒店或机场班车的信息。对于非常常见的任务，如安排旅行，可能需要手动识别并引导用户完成一个任务（当用户试图安排旅行时，预订航班、寻找酒店、寻找兴趣点等）。然而，考虑到搜索引擎所用于的任务的多样性，这可能只适用于其中很小的一部分。此外，搜索引擎经常被用来完成如此复杂的任务，以至于搜索者自己往往缺乏必要的任务知识来决定下一步该处理哪一步。例如，一个搜索者在没有先验知识的情况下寻找关于如何维护汽车的信息，他首先需要使用搜索引擎来识别需要维护的汽车部件，并发出单独的查询来了解如何维护每个部件。因此，需要能够自动检测用户试图实现的任务并引导他们完成该过程的检索系统，其中搜索任务以前被定义为由一组相关（子）任务组成的原子信息需求。尽管设计信息检索（IR）系统能够表征/识别任务，并能够有效地响应它们被列为信息检索的重大挑战之一，但在这个方向上取得的进展很少。本提案的主要目标是设计面向任务的检索系统，检索系统可以自动检测用户试图实现的任务，并指导他们完成完成任务所需的过程（步骤）。

The need for search often arises from a person's need to achieve a goal, or a task such as booking travels, buying a house, etc. Contemporary search engines focus on retrieving documents relevant to the query submitted as opposed to understanding and supporting the underlying information needs (or tasks) that have led a person to submit the query. Therefore, search engine users often have to submit multiple queries to the current systems to achieve a single information need. Having identified that users often have to reformulate their queries in order to achieve their final goal, most current search engines attempt to assist users towards a better expression of their needs by suggesting queries to them, other than the query currently issued. However, query suggestions mainly focus on helping the user refine their current query, as opposed to helping them identify and explore aspects related to their current complex tasks. For example, when a user issues the query "flights to Barcelona", it is clear that the user is planning to travel to Barcelona and it is very likely that the user will also need to search for hotels in Barcelona or for shuttles from Barcelona airport. Since query suggestions mainly focus on refining the current query, suggestions provided by commonly used search engines are mostly of the form "flights to Barcelona from LOCATION", or "FLIGHT-CAREER-NAME flights to Barcelona" and the result pages provided by these systems do not contain any information that could help users book hotels or shuttles from the airport. For very common tasks such as arranging travels, it may be possible to manually identify and guide the user through a list of (sub)tasks that need to be achieved in order to complete a certain task (booking a flight, finding a hotel, looking for points of interest, etc. when the user tries to arrange travel). However, given the variety of tasks search engines are used for, this would only be possible for a very small subset of them. Furthermore, quite often search engines are used for achieving such complex tasks that often the searcher themself lacks the task knowledge necessary to decide which step to tackle next. For example, a searcher looking for information about how to maintain a car with no prior knowledge would first need to use the search engine to identify the parts of the car that need maintenance and issue separate queries to learn about maintaining each part. Hence, retrieval systems that can automatically detect the task the user is trying to achieve and guide them through the process are needed, where a search task has been previously defined as an atomic information need that consists of a set of related (sub)tasks. Even though designing information retrieval (IR) systems that can characterize/identify tasks, and can respond to them efficiently is listed as one of the grand challenges in information retrieval, very little progress has been made in this direction. The main goal of this proposal is to devise task oriented retrieval systems, retrieval systems that can automatically detect the task that the user is trying to achieve and guide them through the process (steps) needed to achieve the task.