Barbara Minto's Pyramid Principle is a technique for communicating complex information. It helps to create a structured hierarchy of ideas.
In essence, the method groups Ideas into small increasingly granular clusters that support the main Thesis. This results in a pyramid structure of ideas, each one expanding to 3 more detailed ideas or concepts.
A Google Image search shows visually how this works.
The method explains how to use the SCQA Framework (Situation, Complication, Question, Answer) which can be used to construct effective FAQ databases for complex knowledge systems.
Book: Barbara Minto - The Minto Pyramid Principle