14.1 Reports are arguments supported by evidence

A professional report is not a container for everything the team produced. It is an organized argument that helps a defined audience understand a problem, evaluate evidence, and decide what to do.

The structure should follow the problem rather than the order of analysis. Data cleaning matters, but the report should not begin with several pages of cleaning detail before the reader understands why the project exists. A complex model may deserve technical documentation without becoming the centre of the client narrative.