The Insignificance of Statistical Significance Testing Replication Replication is a cornerstone of science. If results from a study cannot be reproduced, they have no credibility.
Scale is important here.
Conducting the same study at the same time but at several different sites and getting comparable results is reassuring, but not nearly so convincing as having different investigators achieve similar results using different methods in different areas at different times. Whether any or all of the results are statistically significant is irrelevant. Studies differ in design, measurement devices, samples included, weather conditions, and many other ways. To have generality, results should be consistent under a wide variety of circumstances. Meta-analysis can be dangerously misleading, however, if nonsignificant results or results that did not conform to the conventional wisdom were less likely to have been published.