A few months ago I received an alarming e-mail message from a colleague in my field about some results I had previously published. Even though he was following my protocol, his results differed significantly from mine. Since researchers build on the work of their peers, they must first establish the validity of their colleagues' findings by reenacting their experiments and replicating reported results.
Irreproducible results are deemed unreliable, so progress is impeded.
For this reason, it is important to determine why inconsistencies occur and to reconcile conflicting data. While human error accounts for some irreproducible results, other discrepancies are due to incomplete or inaccurate accounts of methodology in the literature. Even in prominent journals such as Science or Nature, space constraints force scientists to condense explanations of complicated protocols into simplified synopses of their methods. Consequently, important details may be omitted, making it difficult for the reader to duplicate the experiments. In other situations, results are published months or even years after the original experiments were performed, increasing the likelihood that researchers will forget seemingly trivial components of their procedures.