Old-New Information Principle

In situations where a bottom line up front approach isn’t a good fit for an introductory paragraph, a reader may need more information. That is, a writer must decide how much information familiar to the reader s/he will include in the introduction before orienting them to a new topic.

In a full introduction, you can use separate sentences to express old information before new information; in a briefer document or professional email, you may want to include both concepts in the same clear and concise sentence. Both approaches help a reader comprehend what you’re communicating.

Here’s an example from Southern Illinois University; 1b. does a better job of following the old–new information principle. Old information is bold. New information appears in italics.

1a. Some astonishing questions about the nature of the universe have been raised by scientists exploring black holes in space. The collapse of a dead star into a point perhaps no larger than a marble creates a black hole. So much matter compressed into so little volume changes the fabric of space around it in puzzling ways.

1b. Some astonishing questions about the nature of the universe have been raised by scientists exploring black holes in space. A black hole is created by collapse of a dead star into a point perhaps no larger than a marble. So much matter compressed into so little volume changes the fabric of space around it in puzzling ways.