References on a topic concentrate in a few core journals and scatter thinly across many, in a fixed geometric ratio.
Bradford found in 1934 that to double the papers found on a topic you must consult roughly five times as many journals. It is the reason a literature search hits diminishing returns quickly and then falls off a cliff.
In practice
- A researcher finds nine of the twelve useful papers in two journals and the last three across eleven more.
- A support team finds most answers in three documents and spends the rest of the week in forty others.
- Standing
- Completes the Lotka, Price, and Zipf family of concentration laws.
- Subject
- Science & Epistemology
- Essay
- The ways evidence misleads