While multilingual users often switch between languages when seeking information, this process remains undersupported by current systems where information is typically siloed by language. Our formative study reveals that users' cross-language transitions are guided by their perceived value of switching to a language, a concept we formalize as language scent. Language scent extends Pirolli and Card's theory of information scent to multilingual scenarios by considering meta-level strategy formation when navigating between different languages. To support language scent, we designed Niffler, a search system that augments language scent and supports cross-language information navigation through contextual cues, in-situ tools, and reflection support. A lab study with 16 multilingual speakers showed that Niffler facilitated the formation and execution of exploratory and granular search strategies and leads to diverse information being gathered. Our findings establish language scent as a valuable lens on cross-language information seeking, highlighting language's role in enabling access to broader information and offering concrete implications for the design of multilingual search systems.

翻译：尽管多语言用户在信息搜索时经常在不同语言间切换，但当前系统对此过程的支持仍显不足——信息通常按语言隔离存储。我们的形成性研究表明，用户的语言转换行为受其感知的切换价值驱动，我们将这一概念形式化为"语言气味"。语言气味将皮罗利与卡德的「信息气味」理论拓展至多语言场景，通过考虑用户在不同语言间导航时的元级策略形成机制。为支持语言气味，我们设计了Niffler搜索系统——通过上下文线索、原位工具与反思支持来增强语言气味并促进跨语言信息导航。对16名多语言使用者的实验室研究表明，Niffler能促进探索型与颗粒型搜索策略的形成与执行，并带来多样化信息的收集。我们的研究结果确立了语言气味作为跨语言信息搜索的重要分析视角，揭示了语言在扩展信息获取范围中的核心作用，并为多语言搜索系统的设计提供了具体启示。