Ideas are presented in two sections: a problem section and a solution section. Sometimes may be in a question-answer form. May also include an evaluation or consequences of solutions.
Problem, solution, question, answer reasons are many.
history texts, scientific articles political documents...
Example: Rat Allergy
Psychologists who work with rats and mice in experiments often become allergic to these creatures. This is a real hazard for investigators who spend hours a week running rats in experiments. These allergies are a reaction to the protein excretions of rats when they get upset. Therefore it is recommended that experimenters be kind to rats and talk softly to them.