Most of the wikis I know use a variable width for the body text, rather than a narrow fixed width that is common on many websites (including blogs)
This is only because most wiki administrators use the default wiki layout/skin. For the major wiki systems, many layouts exist that use fixed body width. (e.g. Skins for MediaWiki, Skins for PmWiki)
Most of the wikis I know have a separate discussion page, whereas most blogs have a comments section on the same page as the content
In any decent wiki system, it is trivial to put (or mirror/transclude/etc.) the comments onto the main page.
I think wikis tend to have smaller font size than blogs
This is, obviously, trivially customizable.
Wikis make a hard distinction between internal links (wikilinks) and external links, going so far as to discourage the use of external links in the body text in some cases
As mentioned in another response, this seems to just be Wikipedia.
Has anyone thought about these differences, especially what would explain them? Searching variations of “wikis vs blogs” on the internet yields irrelevant results.
What would explain them is just some contingent design choices of the default layouts of some popular systems (e.g. MediaWiki) and some popular wikis (e.g. Wikipedia), and most wiki administrators not really giving a lot of thought to whether to deviate from those defaults.
Links to external sites should be used in moderation. To be candidate for linking, an external site should contain information that serves as a reference for the article, is the subject of the article itself, is official in some capacity (for example, run by id Software), or contains additional reading that is not appropriate in the encyclopedic setting of this wiki. We are not a search engine. Extensive lists of links create clutter and are exceedingly difficult to maintain. They may also degrade the search engine ranking of this site.
Elinks should be constrained to one section titled “External links” at the end of a page. Elinks within the main content of a page are discouraged, and should be avoided where possible.
If you want to link to a site outside of Wookieepedia, it should almost always go under an “External links” heading at the end of an article. Avoid using an external link when it’s possible to accomplish the same thing with an internal link to a Wookieepedia article.
Avoid using external links in the body of a page. Pages can include an external links section at the end, pointing to further information outside IMSMA Wiki.
This is only because most wiki administrators use the default wiki layout/skin. For the major wiki systems, many layouts exist that use fixed body width. (e.g. Skins for MediaWiki, Skins for PmWiki)
In any decent wiki system, it is trivial to put (or mirror/transclude/etc.) the comments onto the main page.
This is, obviously, trivially customizable.
As mentioned in another response, this seems to just be Wikipedia.
What would explain them is just some contingent design choices of the default layouts of some popular systems (e.g. MediaWiki) and some popular wikis (e.g. Wikipedia), and most wiki administrators not really giving a lot of thought to whether to deviate from those defaults.
Here are some examples I found of non-Wikipedia-related wikis discouraging the use of external links:
Doom Wiki:
Sasukepedia:
Wookieepedia:
IMSMA wiki:
Feed The Beast Wiki:
Fair enough—thanks for the examples!
Upvoted for pointing out that it’s a difference in defaults.