Abstract: Starting from the perspective of evidence-based decision-making, this paper explores the relative value of different types of evidence in scientific decision-making by analyzing the population-wide salt reduction. This paper argues that a simple linear relationship cannot be established between "evidence" and policy outcomes. First, the nature of "evidence" from the perspective of evidence-based decision-making is broader than that of traditional scientific evidence, and should include non-scientific evidence including values and civic cognition. Second, when the scientific evidence involved in the policy is controversial, two conflicting claims are often generated from the relevant scientific research, and the relative value of scientific evidence is weakened. Third, policymakers need to carefully consider the various evidentiary value of policy issues, recognize the role that non-scientific factors should play in evidence-based policy making, and avoid being bound by methodological constraints.

摘要： 本文从循证决策视域出发，通过分析英美澳等多国持续数十年的全民减盐政策争议，探讨科学决策中不同类型证据的相对价值。本文认为，不能在“证据”与政策结果之间设定简单的线性关系。首先，循证决策视域下的“证据”比传统科学证据更为宽泛，包含价值观和公民认知在内的非科学证据。其次，当政策涉及的科学领域存在争议时，在科学研究的基础上往往会产生两种互相冲突的主张，科学证据的相对价值会被弱化。再次，决策者需要对政策议题的各类证据价值进行深思熟虑，认识到非科学因素在有据可依的政策制定中应该发挥的作用，避免陷入狭隘的方法论束缚之中。