Conceptual frameworks are developed for evaluating the ability of different biosignatures to provide evidence for the presence of life in planned missions or observational studies. The focus is on intrinsic characteristics of biosignatures in space environments rather than on their detection, which depends on technology. Evaluation procedures are drawn from extensive studies in decision theory on related problems in business, engineering, medical fields, and the social arena. Three approaches are particularly useful. Two of them, Signal Detection Theory and Bayesian hypothesis testing, are based on probabilities. The third approach is based on utility theory. In all the frameworks, knowledge about a subject matter has to be translated into probabilities and/or utilities in a multistep process called elicitation. We present the first attempt to cover all steps, from acquiring knowledge about biosignatures to assigning probabilities or utilities to global quantities, such as false positives and false negatives. Since elicitation involves human judgment that is always prone to perceptual and cognitive biases, the relevant biases are discussed and illustrated in examples. We further discuss at which stage of elicitation human judgment should be involved to ensure the most reliable outcomes. An example, how evaluating biosignatures might be implemented, is given in the Supplementary Information.

中文翻译：

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评估生命检测的生物特征。

概念框架的开发是为了评估不同生物特征的能力，为计划任务或观察研究中生命存在提供证据。重点是太空环境中生物特征的内在特征，而不是它们的检测，这取决于技术。评估程序取自对商业、工程、医学领域和社会领域相关问题的决策理论的广泛研究。三种方法特别有用。其中两个，信号检测理论和贝叶斯假设检验，都是基于概率的。第三种方法基于效用理论。在所有框架中，有关主题的知识必须在称为启发的多步骤过程中转化为概率和/或效用。我们首次尝试涵盖所有步骤，从获取有关生物特征的知识到为全局数量分配概率或效用，例如误报和漏报。由于启发涉及人类判断，而人类判断总是容易出现感知和认知偏差，因此我们将在示例中讨论和说明相关偏差。我们进一步讨论在启发的哪个阶段应该涉及人类判断，以确保最可靠的结果。补充信息中给出了如何实施评估生物特征的示例。