中文摘要：

为发现中文Web用户查询行为的演化趋势,本文对近5年的中文天网搜索引擎的用户日志进行了抽样分析.结果显示：用户输入的查询串中所包含词项数量有明显增多的趋势;用户会话的长度逐年下降;用户查看的结果页面越来越少;查看的时间间隔逐渐缩短;查询串中所包含的汉字个数基本稳定,其中包含2～4个汉字的查询串居多;在查询结果中发生点击行为的比率呈递减的趋势;查询次数与点击次数的相关性逐渐减弱;Web用户查询的主题变化较快.

英文摘要：

In this paper, some key trends in the evolution of Chinese Web searching are discovered, in our sampling analysis of Tianwang＇ s user logs during the last five years. The experiment results show that, the mean number of terms in a single query is significantly increasing, and the mean session lengths is decreasing, as well as the mean number of result pages viewed per query and the mean duration of users＇ viewing. Besides, there is little change in the mean number of Chinese characters appearing in a single query over the five years, and the most common number of Chinese words is 2 ～ 4. The correlativity between the frequency of term appearance in query log and that in click log is getting small. There is a fast drift in user interest contained by Web searching.