A few,such as Williams and Stimatz [8] or Blair-Early and Zender [9] generally refer todesign principles as “rules of thumb”; as such, principles are heuristic methodsthat help us make design decisions quickly. But these rules of thumb can be vari-able and ambiguous, because they are based on individual designers’experienceand on the advice they absorb from their training and reading. Depending on thesituation, designers may employ different design principles at different levelsof consistency.
This statement gives credit to those of the technical communication world which does not happened as often as should. Even though these principles are not set in stone, they give the basics from personal experience, and experience is the best key of learning. One is more prone to listening to one from experience, that may even be considered an expert, than one that is considered practicing or rookie so to say.