For some years now, scientists have gotten increasingly worried about replication failures. In one recent example, NASA made a headline-grabbing announcement in 2010 that scientists had found bacteria that could live on arsenic—a finding that would require biology textbooks to be rewritten. At the time, many experts condemned the paper as a poor piece of science that shouldn’t have been published. This July, two teams of scientists reported that they couldn’t replicate the results.

Article source: http://www.slate.com/articles/health_and_science/science/2012/08/reproducing_scientific_studies_a_good_housekeeping_seal_of_approval_.html