Suter Glenn W, Norton Susan B, Cormier Susan M
U.S. Environmental Protection Agency, National Center for Environmental Assessment, Cincinnati, Ohio 45268, USA.
Environ Toxicol Chem. 2002 Jun;21(6):1101-11.
Biological surveys have become a common technique for determining whether aquatic communities have been injured. However, their results are not useful for identifying management options until the causes of apparent injuries have been identified. Techniques for determining causation have been largely informal and ad hoc. This paper presents a logical system for causal inference. It begins by analyzing the available information to generate causal evidence; available information may include spatial or temporal associations of potential cause and effect, field or laboratory experimental results, and diagnostic evidence from the affected organisms. It then uses a series of three alternative methods to infer the cause: Elimination of causes, diagnostic protocols, and analysis of the strength of evidence. If the cause cannot be identified with sufficient confidence, the reality of the effects is examined, and if the effects are determined to be real, more information is obtained to reiterate the process.
生物调查已成为确定水生群落是否受到损害的常用技术。然而，在确定明显损害的原因之前，其结果对于确定管理方案并无用处。确定因果关系的技术在很大程度上一直是非正式的且是临时的。本文提出了一个用于因果推断的逻辑系统。它首先分析可用信息以生成因果证据；可用信息可能包括潜在因果关系的空间或时间关联、野外或实验室实验结果以及来自受影响生物的诊断证据。然后它使用一系列三种替代方法来推断原因：排除原因、诊断方案以及证据强度分析。如果无法足够确定地识别出原因，则会检查影响的真实性，并且如果确定影响是真实的，则会获取更多信息以重复该过程。
