The two parts of the definition of an organizing system explicitly suggest two categories of requirements, those that specify the intentional arrangement of the resources and those that specify the interactions with the resources. These categories of requirements both depend on resource descriptions, which are implied by but not explicitly called out in the definition of an organizing system.
Because description, arrangement, and interaction are interrelated it is impossible to describe them separately without some redundancy. Nevertheless, in this book we have done that on purpose because taking different perspectives on organizing systems in Chapters 2-9 has enabled us to introduce a broad range of concepts, issues, and methods:
Every organizing system must enable users to interact with its collection of resources (Chapters 2 and 9);
The possible interactions depend primarily on the nature and extent of the descriptions associated with the resources (Chapters 3, 4 and 5);
Intentional arrangement emerges when one or more resource descriptions are used by organizing principles (Chapters 6 and 7);
Different implementations of the same organizing principle can determine the efficiency or effectiveness of the interactions it enables. (Chapter 9).
If you are creating a personal organizing system or otherwise small-scale one with only a small number of users, you might think there is little reason to think explicitly about requirements. ...