Not all evidence is created equal.

Imag­ine a graz­ing strat­e­gy that aims to improve range­land pro­duc­tiv­i­ty and wildlife pop­u­la­tions by incen­tiviz­ing planned graz­ing with access to mar­kets. An assump­tion in the results chain is that if live­stock man­agers fol­low graz­ing plans, they will receive bet­ter mar­ket access. A search of the lit­er­a­ture shows no stud­ies of whether graz­ing com­pli­ance in sim­i­lar pro­grams leads to improved mar­ket access, so the team quick­ly con­ducts some key infor­mant inter­views with live­stock man­agers in an exist­ing, sim­i­lar pro­gram. Some man­agers report receiv­ing bet­ter mar­ket access after imple­ment­ing graz­ing plans, and some report not receiv­ing bet­ter access. You have evi­dence for this link — mul­ti­ple peo­ple have observed whether or not the assump­tion is true. But, the evi­dence is weak because some sup­ports the assump­tion while some refutes it.