Finding a proper mining granularity is a crucial task, which should be finished in the log data preprocess. 摘要在日志数据的预处理中，确定合适的挖掘粒度是一项重要任务。
In order to get the better useful information from the exam data, which with complex and uncertain data, it is necessary to preprocess the source data. 为了更好地从大量复杂的和不确定的考试数据中有效地抢掘有用的信息，必须对源数据进行预处理。
