Offering inquiry study , which is a novelty in the curriculum system of elementary education , complys with the development trend of world curriculum reform . therefore studying inquiry study is a completely new task in the education area . however these studys in our educational field is in a initial stage at present , extensively acceptably frame is n ' t formed , and many unavoidable problems happen in the practice 作为基础教育课程体系中的“新生之物” ，研究性学习的开设顺应了世界课程改革的发展趋势，因此，对研究性学习的研究与探讨是教育领域中的一个崭新课题，然而，目前我国教育界对此课题的研究尚处在初始阶段，还没有形成广泛的可接受性的理论框架，而实践中也出现了许多难以避免的问题。
Then , a new adaptive , on - line , fast samplingstrategy - multi - scaling sampling - is presented inspired by mra multi - resolution analysis and shannon sampling theorem , for quicklyobtaining acceptably approximate association rules at appropriate samplesize . both theoretical analysis and empirical study have showed that thesampling strategy can achieve a very good speed - accuracy trade - off 但是，取样策略必须在算法的效率和结果的精确性之间进行很好的折中， “如何确定合适的样本大小使得运行于其上的关联规则挖掘满足精确性的要求取样复杂性”成为这一方法的关键难解问题。
