Quality assessment term applied | Replication | Sample selection | Other sources of bias |
---|---|---|---|
Yes | Well-replicated (>10 samples per group) | Random or blocked or exhaustive | None evident |
Partially | Moderate level of replication (4–10 samples per group) | Not stated but clearly random or blocked | Potential confounder |
Not at all | Poorly-replicated or not stated (1–3 samples per group) | Purposive or not stated | Clear confounder |