the problem of many scientific studies being difficult or impossible to reproduce by other researchers. This means that the original results may not be reliable or valid, and could be due to chance, bias, or error. The replication crisis affects many fields of science, such as psychology, medicine, economics, and biology.

Some of the causes of the replication crisis are:

  • Publication bias: Journals tend to publish studies that show positive or novel results, rather than studies that show negative or null results. This creates a distorted picture of the evidence and makes it harder to detect false positives.
  • Questionable research practices: Researchers may use flexible or inappropriate methods of data collection, analysis, or reporting to obtain significant or desirable results. For example, they may test multiple hypotheses without correcting for multiple comparisons, manipulate variables after seeing the data, or selectively report only favorable outcomes. These practices can inflate the chances of finding spurious effects and reduce the validity of the findings.
  • Low statistical power: Many studies are conducted with small sample sizes or weak effect sizes, which reduce the ability to detect true effects and increase the likelihood of false negatives. Low power also makes the results more sensitive to random variation and measurement error, and less generalizable to other populations or settings.
  • Lack of transparency and openness: Many researchers do not share their data, code, materials, or protocols with other researchers, which makes it difficult to verify, reproduce, or extend their work. Some researchers may also fail to report important details about their methods or results, such as conflicts of interest, limitations, or alternative explanations. This reduces the accountability and credibility of the research.

the replication crisis is a dangerous threat to the integrity and advancement of science and its benefits for humanity

related: publish or perish