Sample Set of Evidentiary Standards (image) USDA Forest Service - Pacific Northwest Research Station Share Print E-Mail Caption A sample set of evidentiary standards based on a gradient of increasing species rarity. The relative reliability of data types is expected to vary among organism groups. Credit McKelvey et al. Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.