What landmark ruling did the Daubert case establish regarding expert witnesses?

The Daubert case established that trial judges are required to serve as gatekeepers for expert evidence. This means that judges must evaluate the relevance and reliability of scientific testimony before it is presented to a jury. The ruling emphasizes that expert evidence should be based on scientifically valid reasoning and methodology, ensuring that only credible and properly validated scientific information is used in legal proceedings.

This responsibility allows judges to assess factors such as the testability of the expert's theories, their error rate, and whether they have been subjected to peer review, among other criteria. By setting this standard, the Daubert ruling shifted the emphasis from merely accepting expert testimony based on its general acceptance (as it was under the previous Frye standard) to a more rigorous evaluation of its scientific merit. This has significant implications for the quality and reliability of evidence presented in court.