How Audience and Focus Affect Development
All readers have expectations. They assume certain details should be included within certain texts. For instance, readers would be shocked to read NFL statistics in Vogue magazine. Biology students wouldn't expect a paragraph on the artistic value of a pond in an article discussing pond algae.
How you develop your ideas depends on your audience and focus. While it may seem obvious to include certain details, some forms of development work better with particular audiences. Further, your details should work together to support the overall idea of your writing.