Unfair comparison

Equal treatment

Learners in the groups being compared should be treated similarly (apart from the interventions being compared).

If, for example, learners in one group receive more attention and care than people in the comparison group, differences in outcomes could be due to differences in the amount of attention each group received rather than to the intervention(s) being compared.

BEWARE of claims that are based on studies in which comparison groups were not treated equally.

REMEMBER to always check if comparison groups were treated equally.