Attribution

How do readers know where a piece of information came from? Attribution.

Cover shot of writing book by Donald Murray.

Here's a neat definition from "Writing for Your Readers: Notes on the Writer's Craft from the Boston Globe " by Donald Murray, who won the Pulitzer Prize for Editorial Writing in 1954:

"Information in a news story should not float free. It should be anchored to a source so the reader knows where the information comes from. Information can, of course, be attributed to the reporter."

Example of an attribution: 
There are 500 teachers on corrective actions plans (CAPs) due to poor performance, according to Christopher Cerf, superintendent of the Newark school district.

It's about being transparent to your readers.