# Underdetermination of Scientific Theory

> 【EN】At the heart of the underdetermination of scientific theory by evidence is the simple idea that the evidence available to us at a given time may be insufficient to determine what beliefs we should hold in response to it. In a textbook example, if I know that you spent $10 on apples and oranges and that apples cost $1 while oranges cost $2, then I know that you did not buy six oranges, but I do not know whether you bought one orange and eight apples, two oranges and six apples, and so on. A simple scientific example can be found in the rationale behind the important methodological adage that “correlation does not imply causation”. If playing violent video games causes children to be more aggressive in their playground behavior, then we should (barring complications) expect to find a correlation between time spent playing such video games and aggressive behavior on the playground. … 【中】科学理论被证据不充分决定，这一论点的核心是一个简单的想法：我们在某一时刻掌握的证据，可能不足以决定面对它应当持有什么信念。例子是：知道你花十美元买苹果和橙子、苹果一美元、橙子两美元，我能确定你没买六个橙子，却无法确定是否一橙八苹、两橙六苹或别种组合。简单的科学例子则是“相关不蕴含因果”这条箴言背后的理由。

- ID: m13308
- Category: technical
- Domain: 科学方法论

## Definition

不充分决定性的核心想法是：某一时刻可获得的证据，可能不足以决定我们应当据此持有什么样的信念，也就是说证据与理论之间并非一一对应。 脚手架作用：- 竞争构造：为同一组证据主动构造彼此冲突的理论。 - 证据评估：追问新证据能否真正区分两个经验等价理论。 - 选择依据：在证据不足时诉诸简单性等非证据标准。

## How it works

不充分决定性之所以成立，是因为从证据到理论的推理不是演绎：同一组观察可以被多个彼此冲突的理论同样好地容纳。它有多种强度——弱版本只说现有证据不够，强版本则主张存在经验等价却不可调和的理论，再多证据也无济于事。

## Practice

1) 列出能解释同一批证据的所有候选理论；2) 追问它们是暂时的证据不足，还是原则上经验等价；3) 若是后者，明确引入证据之外的标准，如简单性或一致性；4) 说明这些标准的合理性来源。

## Use

- 竞争构造：为同一组证据主动构造彼此冲突的理论。 - 证据评估：追问新证据能否真正区分两个经验等价理论。 - 选择依据：在证据不足时诉诸简单性等非证据标准。

[Read the web page](https://thinkingmodels.site/en/entries/detail/m13308)