2003:56:C918:5568:88B6:6144:27C2:D824 (talk) 11:10, 22 December 2014 (UTC): I have never heard about this part of the definition: "and for which the collection of all contigs of that length or shorter also contains at least half of the sum of the lengths of all contigs. (When more than one value of length meets both these criteria then the N50 is the average of the longest and shortest lengths that meet the criteria.)" Is there a source for this? This definitely has to be cited!!! At least it is NOT mentioned in the publications cited in the article: the Assemblathon 1 and "Assembly algorithms for next-generation sequencing data" papers. So the definitions differ here... So my suggestions are either to properly cite this part or delete it from the article.