At least two INDEPENDENT named studies — different teams or datasets — point the same direction. The only grade that earns "the literature shows".
The definition the product enforces, read from the same code the methodology page renders.
How to read it
When Convergent appears on a page
The only grade that earns the phrase "the literature shows". At least two independent named studies, different teams or datasets, point the same way. Independence is graded separately, and a shared team or a shared dataset does not count as convergence.
The family
Literature review grades
What a body of studies is allowed to be said to show, and whether the question was studied as asked.