I'd like to propose that SI base unit and SI derived unit be merged into this article, International System of Units. The reason for this in summary is that the smaller articles are pretty much already wholly duplicated within this article, and I don't think it makes sense for an article on SI to not include the units. A detailed rationale for this is as follows:

• The majority of the content in SI base unit is already contained in this article. What little different content there is in SI base unit is easily mergable here with minimal increase to this article's length: the section on proposed redefintions is already covered in about as much depth here (and at New SI definitions), and the table of base units is already included here. The histroical justification columns and exact definition columns are missing here but should probably be reworded and included with the table here anyway, as in this table there is a mix of the official definitions and "summarised" definitions, and no references for when each unit was added. I don't believe this information alone is enough to warrant a completely seperate article which by necessity must contain a lot of duplicate information.
• This article already contains everything in SI derived unit and more, and the table "Some SI derived units" in SI derived unit (which is unreferenced and of nebulous quality/use) could easily be added as an expandable section here if required.

CurlyLoop (talk) 09:38, 27 May 2013 (UTC)

Oppose: The article International System of Units contains sufficient for an overview - there is scope to expand the articles SI base unit and SI derived unit, something that UI plan to do in the near future. Moreover the article International System of Units is already 94 kbytes - WP:SIZERULE] suggests that articles of this size should be divided, not have content merged into them.Martinvl (talk) 10:18, 27 May 2013 (UTC)

That's fair enough, but what exactly is there scope for adding to SI base unit and SI derived unit? I don't beleive that it's sufficient to say that there is scope without clarifying for what in this instance as it's not obivous to me what more could be added to either of these articles that justifies their individual existence. What sort of changes do you imagine happening to them? The articles have been around for a long time and have ended up in a very measly state indeed - as I've said already all the current content is duplicated here. I take your point about the size guideline. Thanks for your comment. CurlyLoop (talk) 11:11, 27 May 2013 (UTC)

The article SI derived unit is currently classed as a list-class article and contains a lot of material that is not in the article International System of Units. As such it would be inappropriate to move the contents of that article into the article International System of Units. The article SI base unit can be extended by a new section entitled "Background" which would discuss the concept of base units with particular reference to the problems of Maxwell and Kelvin in respect of electrical units, how Giorgi in 1900 proposed adding an electrical unit as a fourht base unit. This would then be followed by a discussion of why, in 1960, the MKS system rather than the CGS system was chosen as the basis of SI and of how SI originally had five base units, but why there are now seven such units. Martinvl (talk) 11:36, 27 May 2013 (UTC)

That sounds like a very reasonable (and interesting!) way of expanding that article; thanks for detailing your ideas. It would certainly give SI base unit more of a reason to exist. I'm not sure I agree with your view that there's "a lot" of extra material in SI derived unit but we'll see if any other editors have specific comments on that. CurlyLoop (talk) 20:17, 27 May 2013 (UTC)

How about (also) merging SI base unit and SI derived unit? I don't think they both should be merged here (this article is big enough as it is, as mentioned above) but they could reasonably be merged together into an SI unit article. JIMp _talk·cont 02:57, 28 May 2013 (UTC)

I don't think it practical to merge the two articles SI base unit and SI derived unit as they are different types of article - in particular SI derived unit is classed as a list class article while SI base units is a normal article. Martinvl (talk) 05:26, 28 May 2013 (UTC)

... if they were merged, though, it'd be a normal article with lists ... just a thought anyhow. JIMp _talk·cont 05:38, 28 May 2013 (UTC)

Since the underlying concepts between base units and derived units are so different, the result would be a rather disjointed article. Martinvl (talk) 16:49, 31 May 2013 (UTC)