After Ellen Page chose the general subject of “malaria prevention” and searched her library catalog to get a feel for the kinds of information available on her subject, she considered which conversations she might join by clustering. She placed the words malaria prevention at the center of her cluster and then wrote questions about her subject. She used the questions to explore strategies that had been used in the past century to prevent malaria, the advantages and disadvantages of those strategies, and approaches that are now in use. She represented her answers to these questions as words or phrases linked to each question.

After considering her assignment and writing situation, Ellen decided to focus on the advantages and disadvantages of using DDT to prevent malaria. She felt that this focus would allow her to accomplish her purpose of informing her readers about an important issue and believed that it would interest both her and her readers. She knew that the effects of DDT in agriculture had led to a ban on its use in most of the developed world, but she had also found articles that showed how it was being used to prevent malaria in developing countries. She decided that it would be possible to present a balanced, informed assessment of the use of DDT.