Review (RVW) Module for RSS 2.0

Specification Version: 0.1.1 (draft)

May 2003

http://www.purl.org/NET/RVW/

Author

Alf Eaton <a@pmbrowser.info>

Abstract

This specification defines the Review (RVW) Module for the RSS 2.0 syndication format. RVW is intended to allow machine-readable reviews to be integrated into an RSS feed, thus allowing reviews to be automatically compiled from distributed sources.

Usage

Many people publish reviews on their own websites, but it is currently difficult to take all these opinions into account when making a decision. Individual reviews may have their own rating scheme, may lack a definite description of the subject of the review, and may be of books, music, films, restaurants, beaches, politicians, or any other subject. As online product reviews become [increasingly widespread], it becomes more important to make these critical opinions easily accessible on demand.

While RDF can be embedded into weblog posts, the ease of use of RSS to semantically describe the content of the post, and the prevalent use of RSS by desktop and server-side aggregators, makes this format the ideal choice for the addition of metadata to reviews. There is, however, no objection to transforming this data into RDF if particular purposes may be better served.

The inclusion of RVW metadata in RSS feeds where appropriate will enable the building of aggregators that can collate reviews in particular topic areas, aggregate rating scores, and summarise the opinions of a huge number of contributors, with the aim of providing informed analysis to those who need it.

Example Format

<?xml version="1.0"?>
<rss version="2.0"
        xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
        xmlns:dc="http://purl.org/dc/elements/1.1/"
        xmlns:ent="http://purl.org/NET/ENT/1.0/"
        xmlns:foaf="http://xmlns.com/foaf/0.1/"
        xmlns:rvw="http://purl.org/NET/RVW/0.1/">
        <channel>
                <title>HubLog</title>
                <link>http://www.pmbrowser.info/hublog</link>
                <description>Alf's reviews feed</description>
        
                <item>
           	    <title>The review headline goes here</title>
           	    <link>http://www.pmbrowser.info/hublog/archives/1234.htm</link>
           	    <description>The body of the review goes here.</description>
           	    <dc:date>2003-05-08T01:01:01+00:00</dc:date>
           	    <dc:creator>
           	            <foaf:person>
           	                    <foaf:name>alf eaton</foaf:name>
           	                    <foaf:mbox_sha1sum>4057e48e7bf04a1bead63f9c6d18b4245a52db03</foaf:mbox_sha1sum>
           	            </foaf:person>
           	    </dc:creator>
           	    <rvw:item>
           	            <rvw:link>http://www.amazon.com/exec/obidos/ASIN/0156027321/</rvw:link>
           	            <dc:identifier>ASIN:0156027321</dc:identifier>
           	            <dc:type>Text</dc:type>
           	            <dc:title>Life of Pi</dc:title>
           	            <dc:creator>Yann Martel</dc:creator>
           	            <dc:publisher>Harvest Books</dc:publisher>
           	            <dc:date>2003-05</dc:date>
           	            <ent:cloud ent:href="http://www.pmbrowser.info/rvw/">
           	                    <ent:topic ent:id="paperback" ent:classification="book" ent:href="http://www.pmbrowser.info/rvw/types.xtm#book">paperback</ent:topic>  
           	            </ent:cloud>
           	            <rvw:rating>
           	                    <rvw:minimum>0</rvw:minimum>
           	                    <rvw:maximum>10</rvw:maximum>
           	                    <rvw:value>7</rvw:value>
           	            </rvw:rating>
           	    </rvw:item>
                </item>
        </channel>
</rss>

The RSS item containing the review is found within an RSS channel which provides the title of the RSS feed, a link to the base URI of the site, and a brief description of the feed's contents.

The item contains a title (the review headline), a link to a URI where the individual review can be permanently found, the full text of the review (in the description field), the date of the review and information about the reviewer, including a unique identifier.

The rvw:item section contains information about the subject of the review, including a categorisation of the subject, metadata describing the subject, a unique identifier if available, and a rating on a defined scale.

rvw:item contents

• rvw:link points to a page where full information can be found about the subject

• dc:identifier contains a unique identifier prefixed by the type of identifier used. This could be ISBN?, ISSN? or any other acceptable standard.

• The other dc fields are all defined in the [Dublin Core specifications].

• The ENT namespace uses the Easy News Topics specification to describe the type of subject under review. This allows the use of a wide range of subjects, which can be defined by the reviewer within the ent:topic field as needed, if not already defined elsewhere. Reviews from separate sources can therefore describe the same topic using different vocabulary, but identical topics can be linked together further downstream.

• The rvw:rating field contains maximum and minimum possible ratings, plus the actual rating score given by the reviewer. This allows different reviewers to use different scales, eg 1 to 5, 0 to 10, 0 to 100, or -5 to 5.

Usage

Feedback

This is a draft specification. Please send feedback to a@pmbrowser.info

Changes

October 2003: added ent:classification

December 2003: deleted reference to Movable Type plugin - still looking for a better way to add metadata.