How the Unread Index Works
The Unread Signal exists to find developments in imaging, radiation and nuclear science that matter more than the attention they have received. The Unread Index is how we show that judgment and the work behind it.
Two measures
Significance is scored out of 10 against five criteria, each worth 0, 1 or 2 points:
- Strength of evidence. 2 for randomized or sham-controlled trials, regulatory decisions and primary records; 1 for large observational studies, registries and official reports; 0 for press releases, case reports and single announcements.
- Effect on practice or understanding. 2 if it challenges or changes current practice, guidelines or the accepted account of an event; 1 if it informs them; 0 if it has no direct effect.
- Reach. 2 for many patients, sites or workers; 1 for a single specialty or region; 0 for a niche.
- Stakes. 2 for clear safety, dose or cost consequences; 1 for indirect consequences; 0 for little at stake.
- Surprise. 2 if it contradicts what most people in the field assume; 1 if it adds meaningfully; 0 if it confirms the expected.
Each score comes with a one-line reason, shown under “How we scored this” on the story.
Coverage is what we found when we searched for other reporting on the same development. For recent news, we search from the date of the development. For historical stories, we search the past five years, because the question is whether the story is known today. Only mainstream news, trade press and journal commentary are counted, meaning outlets publishing their own reporting or analysis. Press releases and their reposts are listed but not counted, and so are other sources, such as encyclopedias and reference sites, stock-news sites that summarize announcements, law-firm alerts, blogs and social posts. The original sources a story cites are not counted as coverage either.
Because the count includes only reported coverage, a story can score high and still be labeled Widely covered. That means it matters and is already getting attention.
The labels
- Unread: significance of 7 or more, and no more than two outlets found.
- Underread: significance of 7 or more, and three to six outlets found.
- Under the radar: significance of 4 to 6, and no more than two outlets found.
Every scored story shows its score. Stories outside those ranges get a plain coverage note instead: Widely covered (seven or more outlets), Covered (three to six) or Low profile (two or fewer). A story without one of the three labels is not less important; it may simply have been well covered elsewhere.
See every story side by side on the Unread Index Rankings.
What the index cannot do
Searches miss things. The index reports the coverage we found on the date shown, not every story ever written, and we list every outlet so readers can judge for themselves. Significance is an editorial judgment made against a fixed rubric, not a measurement. If you know of coverage we missed, tell us and we will update the story.