Readers of documentation value these qualities.
Gretchen Hargis et al. organize the qualities by grouping them. They define three groups for readers of documentation:
- Easy to find
- Easy to understand
- Easy to use
These quality attributes are associated with these groups.
While Hargis et al. use the term group to organize quality attributes, we refer to this groups as values. 'Easy to find' is therefore also a value of documentation that is addressed by maximizing the quality attributes organization, retrievability, and visual effectiveness.
The selection of nine quality attributes may seem a little arbitrary at first. In their book Developing Quality Technical Information (Gretchen Hargis, Michelle Carey, Ann Kilty Hernandez, Polly Hughes, Deirdre Longo, Shannon Rouiller, Elizabeth Wilde) the authors show how other quality attributes relate or are actually part of these fundamental nine quality attributes. For each quality this book provides plenty information and examples on how to create documentation with these qualities.
We won't go into more detail here. For more information on this topic we recommend: Read this book! 
Reducing the amount of quality attributes to nine and grouping them into three groups makes qualities easier to manage. Nonetheless creating quality documentation is an iterative process. The quality attributes also do not demand a specific process, may it top-down or bottom up, agile or not.
