Yahoo! Trending Now lists the most trending ten user queries from Yahoo! Search. To discover top trending queries, query clustering is a critical intermediate phase that aggregates similar queries into clusters, each representing an event or a topic. Established on a heuristic clustering framework, the existing approach can generate suboptimal results but lacks the ability to: 1) fully exploit semantic information in news articles associated with user queries, and 2) account for changes in queries and news articles over consecutive timestamps. In this paper, we first introduce a two-stage query clustering framework that leverages both match-based grouping and distance-based clustering. This novel and effective solution significantly surpasses the existing production method. Furthermore, to address the challenges posed by high time complexity and potential cluster fluctuations on account of temporal factors, we optimize the newly proposed framework by 1) utilizing a caching mechanism to store historical query features to enhance computational efficiency, and 2) applying voting and rolling average strategies at the time window level to both stages, respectively, resulting in smoother feature representations and more robust clustering out-comes. Through offline evaluation, our integrated method speeds up the baseline by 20 times and reduces cluster fluctuations by 15 times. These improvements considerably enhance the efficiency and stableness of query clustering for Yahoo! Trending Now.

The GetSmart system was built to support theoretically sound learning processes in a digital library environment by integrating course management, digital library, and concept mapping components to support a constructivist, six-step, information search process. In the fall of 2002 more than 100 students created 1400 concept maps as part of selected computing classes offered at the University of Arizona and Virginia Tech. Those students conducted searches, obtained course information, created concept maps, collaborated in acquiring knowledge, and presented their knowledge representations. This article connects the design elements of the GetSmart system to targeted concept-map-based learning processes, describes our system and research testbed, and analyzes our system usage logs. Results suggest that students did in fact use the tools in an integrated fashion, combining knowledge representation and search activities. After concept mapping was included in the curriculum, we observed improvement in students' online quiz scores. Further, we observed that students in groups collaboratively constructed concept maps with multiple group members viewing and updating map details.