RISK CHARACTERIZATION AND THE WEIGHT OF EVIDENCE - ADAPTING GATEKEEPING CONCEPTS FROM THE COURTS

Risk characterization objectives include evaluating the weight of evid ence underlying risk determinations, communicating that evaluation to nonexperts, guiding risk assessors to achieve consistency, and preserv ing deference for those reasonable expert judgments inherent in any ri sk determination. Similar objectives are shared by American courts tha t face the gatekeeping task of screening scientific evidence before it is presented to nonexpert factfinders, such as juries. This article s urveys the judicial gatekeeping concepts of relevance, evidentiary rel iability, legal sufficiency, presumptions, and standards of proof part icularly, preponderance of the evidence). It examines recent court dec isions that have applied these concepts to the kinds of scientific inf ormation common in risk assessments, and suggests how to adapt these g atekeeping concepts for use in weight-of-evidence characterization. If we can develop and adopt a neutral framework for characterizing the w eight of evidence underlying risk assessments, it might help clarify n ot only the current debate over risk characterization and risk managem ent, but also the drafting of treaty provisions, such as those invokin g the Precautionary Principle of international environmental law.