Understanding what you know, think or believe about a topic is essential if you are to write clearly about that topic. Yet it is often difficult for young writers to know what they think and, certainly, even more difficult for them to organize their thinking. Simply telling students to write more clearly or to make their point more effectively will not make them able to do so. They must be taught how to become aware of their thoughts and feelings and how to organize them to effectively communicate them through their writing.
Steele, J. L., & Steele, P. (1991). The Thinking-Writing Connection: Using Clustering to Help Students Write Persuasively. Reading Horizons: A Journal of Literacy and Language Arts, 32 (1). Retrieved from https://scholarworks.wmich.edu/reading_horizons/vol32/iss1/5