The numbering of things

The numbering of archival scientific journal articles is a surprisingly complicated subject. This is both more true and less true in the age of digital, online publications. It is more true because in addition to the classical numerical identifiers of year, volume, issue, and page, we now have the URL (Uniform Resource Locator) and DOI (Digital Object Identifier). Furthermore, some journals, including the Journal of Vision, have added an article number to the list of identifiers. But identifying a unique article is simpler in the digital age than in the past if that article makes use of the DOI. This is a unique string that in principle identifies a particular article. In the Journal of Vision, each article is identified by a DOI. For example, one recent article has the DOI: 10.1167/6.9.1. In the future, we may hope that all scientific journals will ensure that each article, and citation, includes a DOI, and we may further hope that search and indexing services will make consistent use of this information. But until that day, we are obliged to continue to number and group articles in more or less conventional ways. Since launching, the Journal of Vision has numbered pages in a fashion that is traditional in many journals: page numbers increase sequentially throughout the year. This leads to a number of complications. In particular, it is difficult to prepare multiple papers in advance, and it is difficult to arrange parallel publication of special issues (Watson, 2006). But beyond these practical difficulties, annual pagination violates the spirit of the numbering hierarchy that is observed elsewhere in the Journal of Vision. As reflected in our URL, DOI, and Table of