Understanding Knol URLs

Knol URLs

Knol URLs (Uniform Resource Locators) are generally of the following form:

What do these components mean?

• The /k/ is a routing prefix, which points to all knols hosted under knol.google.com. The other URL prefixes we use are somewhat obscure and internal. We use /c/ for authors' thumbnail images, /data/ for hosted audio knols, and /reviews/ for the star ratings we show. There may be additional routing codes in the future.
• The <author> component is the knol's first owner's name, with uppercase letters converted to lowercase, spaces converted to dashes, non-alphanumeric characters dropped (so no non-Roman character sets), and truncated to a maximum length. If the author's name consists solely of non-Roman characters, it turns into a single dash character "-". At no time does the <author> field completely empty out.
• The <title> component is the knol's title, again transformed in the same manner as the author name.
• The <identifier> component is a code permanently associated with the author's Google Account.
• The <number> is how many knols you have ever created (including blanks and deleted knols). So ".../123" is your one-hundred and twenty-third knol.

Tricks with Knol URL parameters

Knol urls contain a few useful query parameters.

• You can view a knol in another language (if that language is supported), adding ?hl=<language code> as a query parameter to the URL. Example: the home page in Arabic.
  
• You can view a knol as if coming from another country (if we have a separate domain-launch for that country), by adding ?gl=<country code>. Example: the English language home page with Korean styling (that is, using the same layout as the http://knol.google.co.kr/k home page.)
  
• You can make a permanent link to a past version by adding ?version=<version number> as a query parameter to the URL.

Tricks with Knol URL anchors

• If you want a link to a knol to pop you straight into edit mode, use #edit on the end of the URL. Example:
  
  http://knol.google.com/k/-/-/si57lahl1w25/109#edit
  
  This is useful to direct visitors to come and edit an open collaboration knol. However, please avoid using it on closed collaboration mode knols.
  
• If you want to create a manual reference list, see: Linking to places in the same knol.
• If you want to see the difference between two versions of a knol, you can add #revisions-compare-<first_version>-<second_version>. For example:
  
  http://knol.google.com/k/scott-jenson/buttermilk-pancakes/IMd1ml4q/vzc3bg#revisions-compare-43-53
  
  Shows the changes in Scott Jenson's "Buttermilk Pancakes" knol going from version 43 to 53.
• The knol document zero (/0) for any given author always points to that person's Bio page. Example: http://knol.google.com/k/-/-/si57lahl1w25/0. You can add #knols, #reviews, #comments, #coowners, or #coauthors to the URL in order to see the various sub-lists within the bio page.

FAQs about Knol URLs

Q: But my knol URL is too long!

If you want a shorter URL, the name and title portions are "dont care" fields. You could replace the author and title fields with dashes, and the link still works. So here is another equally good but more compact way of linking to this document: http://knol.google.com/k/-/-/si57lahl1w25/109 .

Q: How else can I get shorter URLs?

Here are a few suggestions.

First, you can use an external service such as http://tinyurl.com to generate "short" URLs to you favorite knols, and you can bookmark those or email those to your friends.

Second, you can use search-based URLs. These do not point to a specific URL, rather they invoke a search and point to the published knol that best matches the search. For example, you can use a URL with the following form:
    http://knol.google.com/<author>/<title>

We will try searching for a page whose author name matches <author> and whose title matches <title>. Here is an example:
    http://knol.google.com/k/julian/knol-feature-requests

While this form of URL is compact and human-readable, it is not guaranteed to be a permanent URL. If there is more than one author named "julian" or more than one knol with the title containing the keywords "knol feature requests", then we return a search results page instead of a specific knol.

Q: How do I get a URL that points to just my knols?

Click on "By Bio" then select the Knols tab. It will take you to link such as this:
    http://knol.google.com/k/knol-help/-/si57lahl1w25/0#knols
That shows your published knols. You can make the url shorter if you repllace the author component with a dash. Here is an example:
    http://knol.google.com/k/-/-/si57lahl1w25/0#knols

Q: I'd prefer URLs allowing just the author name and the article name. That seems like a more self-explanatory system.

A: It is true that titles such as you suggest might seem more readable. But a naming scheme that just directly used name + title does not work in general. Some relevant issues include:

1. Author names and knol titles are not necessarily unique. For example, we can have two people named Anonymous (not that we encourage that!), and two knols about Barack Obama.
   
2. Names and titles may need to be truncated, if overly long.
   
3. Names and titles may contain whitespace, which gets trimmed and turned to "-" in a URL, and Names and titles may contain characters which are not legal in a URL.
4. Names and titles using something other than the Roman character set don't necessarily translate into anything human-readable within a URL.
5. We wanted our basic URLs to directly map onto permanent URLs that can be durable across changes to an author's name or title, and across transfers of ownership between authors.
   

Q: But none of those problems you just listed apply to my knols! Why can't I have a simpler URL? Can't I just suggest a URL and claim it for my use if it is not taken?

A: We have an open feature request to give authors additional choices over their URLs. But for now we are going with a system which works for all the use-cases, even if it is awkward for some people.

Q: If I change my user name, will my links still be valid? Will that affect my search engine performance or page rank?

A: Yes, any links containing URLs to the old name will redirect to the new URLs, so any users who follow the old links will arrive at the new pages.

Search Engine ranking is comprised of a very large number of signals, including Page Rank. While Page Rank will flow to the new URLs, it is possible that some signals will not transfer. A highly ranked or popular page could suffer some loss in search engine ranking on google.com and/or in other search engines. This should be a temporary effect.

Q: My long-form URL has some Page Rank, but my short forms of the same URL show no Page Rank. Is that a temporary effect?

A: No, that effect is intentional  and permanent.

First of all, in case anyone doesn't know it, you can see the approximate Page Rank Google assigns to a web page if you install the Google Toolbar in your browser, and enable the feature.

Long URLs are canonical

While there are multiple URLs which show the same content, all of the variants will indicate the long form as canonical. (See this explanation of the rel="canonical" html tag for a video with an in-depth explanation.)

You are free to use the shorter forms. However, the long form, for example:
will ordinarily be the one that gets Page Rank and surfaces in search results, not any of the shorter forms: