Studies with low quality ratings demonstrate little evidence that findings are attributable, in part or in full, to the intervention examined. A low quality rating suggests that there is a high risk of bias. The Pathways Clearinghouse focuses on providing detailed information for studies rated high or moderate quality because these studies have a lower risk of bias, and these interventions are more likely to have contributed to the reported outcomes.

The Pathways Clearinghouse estimates effect sizes for each finding with a high or moderate rating when the study or study authors provide sufficient information to calculate an effect size. The Pathways Clearinghouse team contacts authors to obtain the information necessary to calculate the effect size, but in some cases, sufficient information is not available.

An effectiveness rating is the assessment of the Pathways Clearinghouse, based on the existing evidence from impact studies, of the extent to which a given intervention improves a specific type of outcome. The effectiveness rating is a holistic assessment of whether an intervention is likely to produce favorable results if faithfully replicated with a similar population. An effect size is a standardized measure that allows us to make direct and meaningful comparisons across different outcomes, settings, and interventions.

An effectiveness rating assesses whether an intervention is likely to produce favorable results if faithfully replicated with a similar population. Outcome domains with well-supported ratings are those that the evidence suggests are most likely to improve if an intervention were replicated with a similar population. Outcome domains with supported ratings have some evidence that the intervention improves them, but the evidence is less conclusive.