Pseudoreplication is (still) a problem.

Hurlbert (1984) laid out a rationale for why experimental designs need to consider statistical problems related to pseudoreplication of data. This paper has been a cornerstone for more proper experimental design in many fields. Nonetheless, Schank and Koehnle (2009) argue that pseudoreplication is no longer a relevant issue. We disagree with this conclusion. We list a number of distortions of the original Hurlbert paper that are found in Schank and Koehnle. In addition, we note that some of the original suggestions in Hurlbert are no longer valid because statistical techniques have inevitably evolved to provide stronger tests than were available 25 years ago.