Rules of thumb exist for interpreting SMDs (or ‘effect sizes’), which have arisen mainly from researchers in the social sciences. One example is as follows: 0.2 represents a small effect, 0.5 a moderate effect, and 0.8 a large effect (Cohen 1988). Variations exist (for example, <0.41 = small, 0.40 to 0.70 = moderate, >0.70 = large). Review authors might consider including a rule of thumb in the Comments column of a ‘Summary of findings’ table. However, some methodologists believe that such interpretations are problematic because patient importance of a finding is context-dependent and not amenable to generic statements.