Rigorous evaluation refers to a systematic, thorough, and methodologically sound process used to assess the effectiveness, impact, or quality of an intervention, program, or policy. It emphasizes the use of robust study designs (such as randomized controlled trials, quasi-experimental designs, or longitudinal studies), transparent criteria, and objective data to ensure that the findings are valid, reliable, and replicable.

In summary:

Rigorous evaluation is the process of assessing outcomes using scientifically credible methods that minimize bias, control for confounding factors, and produce dependable evidence for decision-making.