Van Dijk's ideas about superstructures and macrostructures provide a way to understand how people, including classifiers, mentally perceive the main topics of written texts. These concepts could be useful for studying how people categorize documents.

To summarize, I could say that Michael K. Buckland argues that information can be understood in three ways: as a process, knowledge, and a thing. Buckland focuses on the third aspect, emphasizing that tangible objects like documents and data sets can be considered forms of information. These "things" are crucial for preserving, transferring, and retrieving knowledge. In the field of information science, understanding these physical carriers of information is essential for understanding how information is used and managed.