Good experimental design is critical for sound empirical ecology and evolution. However, many contemporary studies fail to replicate at the appropriate biological or organizational level, so causal inference might have less vigorous support than often assumed. Here, I provide a guide for how to identify the appropriate scale of replication for a range of common experimental designs in ecological and evolutionary studies. I discuss the merits of replicating multiple scales of biological organization. I suggest that experimental design be discussed in terms of the scale of replication relative to the scale at which inferences are sought when designing, discussing and reviewing experiments in ecology and evolution. I also suggest that more conversations about experimental design are needed, and I hope this piece stimulates such conversation.

中文翻译：

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生态学和进化实验设计原理

良好的实验设计对于健全的经验生态学和进化至关重要。然而，许多当代研究未能在适当的生物学或组织水平上进行复制，因此因果推断可能没有像通常假设的那样得到强有力的支持。在这里，我提供了如何确定生态和进化研究中一系列常见实验设计的适当复制规模的指南。我讨论了复制多种规模的生物组织的优点。我建议，在设计、讨论和审查生态学和进化方面的实验时，应该根据复制的规模来讨论实验设计，而在复制的规模上寻求推论的规模。我还建议需要更多关于实验设计的对话，我希望这篇文章能够激发这样的对话。