The importance of exploring the Web through trial and error has been increasing in proactive works such as Project-Based-Learning (PBL). In such exploration, it is important for learners to accurately understand the content of the acquired pages and express their search intentions in the form of new search queries on the basis of it. However, this is clearly difficult for unskilled learners. Although there have been many research projects on supporting Web exploration, most of them have targeted only the efficiency of exploration and have not considered the development of skills. In this research, we aimed to develop a strategy for cultivating in students practical skills for complicated Web exploration. In particular, we focused on the phenomenon that the search intentions of unskilled people are unconsciously embodied in their behaviors when selecting pages. We developed methods for generating clues for main tasks in complicated exploration that are based on the analysis of learners' behaviors. We also designed a strategy for cultivating practical exploration skills by offering these clues to unskilled students and reducing the number of them step by step. This paper mainly describes the framework of the proposed methods. Moreover, we describe experiments on extracting the clues and discuss the characteristics of our methods on the basis of the results.