Re: Linked Data and Semantic Web CoolURIs, 303 redirects and Page Rank.

Hello Mark,

I cannot remember this important topic coming up earlier - which is a bit
disturbing.

The problem would be migitated by people using the URI they see for linking.

Why not use the HTML URLs in the HTML pages for internal page rank flow?

How can URIs from sparql endpoints or OAI-PMH contribute to page rank?

A real problem would be RDFa where href also sets the object of a triple.

Regards,

Michael Brunnbauer

On Fri, Jul 18, 2014 at 10:05:17PM +1000, Mark Fallu wrote:
> If the links we present to the outside world for harvesting eg. via sparql
> endpoint, OAI-PMH or open social widget etc is the canonical "individual"
> URI, clients will be able to get to the "display" url, but the google page
> rank that would normally flow from these external links will not.



> 
> The specification of a 303 redirect describes it as:
> http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html
> 
> > "The response to the request can be found under a different URI and SHOULD
> > be retrieved using a GET method on that resource. This method exists
> > primarily to allow the output of a POST-activated script to redirect the
> > user agent to a selected resource. *The new URI is not a substitute
> > reference for the originally requested resource*. The 303 response MUST
> > NOT be cached, but the response to the second (redirected) request might be
> > cacheable.
> >
> 
> 
> The different URI SHOULD be given by the Location field in the response.
> > Unless the request method was HEAD, the entity of the response SHOULD
> > contain a short hypertext note with a hyperlink to the new URI(s)."
> 
> 
> Google correctly implements the specification and does not assign the page
> rank of the "individual" URI to the "display" URL as it is "*not a
> substitute reference for the originally requested resource".*
> 
>  The same is true of internal links, a high page rank home page will not
> pass page rank on to "display" urls if the pathway to those urls is via
> "individual" uri links.
> 
> I am not sure what the solution is here as it seems the realms of SEO and
> the conventions of the web they are built on are not a good fit for
> semantic web best practice.
> 
> The most minimal compromise I can think of is to move away from the use of
> a 303 redirect to a redirect that conserves the flow of google page rank.
> 
>    - "302 Found" redirect is the recommended replacement for 303 for
>    clients that do not support HTTP 1.1  and it does allow a certain amount of
>    google page rank to flow.
>    - "301 Moved Permanently" is a poor fit for the Cool URI pattern, but
>    passes on the full page rank of the links.
>    - rewriting all URIs the URL would also work, but would break the
>    coolURI pattern.
> 
> The pragmatist in me feels that if we are going to make a change for the
> purposes of SEO, it might as well be the one with best return, i.e. 301
> redirect.
> 
> Note: Indexing is not the problem here, content is indexed.  The issue
> relates to page rank not flowing through a 303 redirect.
> 
> I have tested and can confirm that 303 redirects are an issue for a number
> of reasons:
> 
>    - page rank does not flow through a 303 redirect
>    - page rank can not be assigned from a url to a uri with a rel=canonical
>    tag if URI does a 303 redirect (preventing aggregation of pagerank from
>    external links to URL)
>    - URI and URL are indexed separately
>    - rdfa schema.org representations of URIs do not translate to URL (ie.
>    representation described at URL A, talking about URI B, does not get
>    connected to representation described at URL B)
>    - url parameters are not passed by a 303 redirect.
>    - impact on functinality of google analytics tracking eg. traversing the
>    site is seen as a series of direct page visits.
> 
> Essentially - as far as search engines are concerned - every URL and URI is
> an island, with no connections between them.  At best a URL can express a
> rel=canonical back to it's corresponding URI, no pagerank will flow through
> links.
> 
> Any guidance you can provide would be appreciated.
> 
> -- 
> 
> o-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
> | Mark Fallu
> | Manager, Research Data (Acting)
> | Office for Research
> | Bray Centre (N54) 0.10E
> | Griffith University, Nathan Campus
> | Queensland 4111 AUSTRALIA
> |
> | E-mail: m.fallu@griffith.edu.au
> | Mobile:  04177 69778
> | Phone:  +61 (07) 373 52069
> o-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

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