RSS. Tina Jayroe. University of Denver

Transcription

1 RSS Tina Jayroe University of Denver Web Content Management Shimelis G. Assefa, PhD February 18, 2009

2 A syndication feed is simply an XML file comprised of meta data [sic] elements and in most cases some content as well. Hunter, Watt, Rafter, Duckett, Ayers, Chase, Fawcett, Gaven & Patterson, 2004, p. 482 RSS is a markup language file format that uses text (or tags) to point to, describe, and automatically feed content from servers to clients; it is considered a flavor of XML (Morris, Tomasi & Terra, 2008, p. 210). The latest version of the syndication language, RSS 2.0, stands for Really Simple Syndication. Previous versions, RSS 0.9/1.0 and RSS , are known as RDF Site Summary and Rich Site Summary respectively. RDF or Resource Descriptive Framework is a World Wide Web Consortium (W3C) universal resource identifier standard that forms the structure on which RSS is based (Hunter et al., 2004, p. 486). The idea of syndicated feeds originated from Apple Computer, Inc. 1 in the mid-1990s as a way to publish content using push technology (Hunter et al., 2004, p. 484). However, it wasn t until Microsoft developed its Content Definition Format (with the goal of delivering content to broadcasting companies by distributing it through channels ), along with Netscape Communications Corporation s submission of Meta Content Framework, that the W3C determined RSS should become a standard metadata language format (Hunter et al., 2004, pp. 485, 486). Hunter et al. state that feeds are where syndication and metadata meet so as to deliver content with a huge amount of versatility in systems (2004, p. 482). RSS is able to deliver content that can be parsed and reused with little or no programming knowledge (Yee, 2008, p. 77), and is now known as a pull technology. That is, once an aggregator/newsreader/feedreader is employed, it lets the subscriber know when something new has been published from a server/database/web site, relinquishing the need to constantly check the publishing source. Therefore, the true benefit of RSS distribution lies in the timeliness of the information. file s contents: All RSS files start with a declaration statement that consists of two lines of text that describe the <?xml version= 1.0?> <rss version= 2.0 xmlns:content= 2

3 These two lines tell the RSS reader that the document is written in XML version 1.0 with a flavor (modified version) of RSS 2.0 (Morris et al., 2008, p. 213). The tags (or elements) that must be used in RSS formats are: the root element <rss> a child of the root element or the <channel>, which contains the contents of the feed and the elements to describe it the <title> element: the name of the feed/web site the <link> element: the URL that the feed refers to the <description> element: a very brief summary of the feed A channel can have many item elements which pertain to individual episodes of a feed or specific attributes, e.g., the <enclosure> or <content:encoded> tag for podcasts. Thus, each <item> must have at the very least a <title> and <description> element. Items would most likely contain the elements <pubdate> and <link> as well. The RSS file must be ended or closed with the </rss> tag (Morris et al., 2008, p. 226). Figure 1. The <channel> element of an RSS 2.0 feed contains information about the feed in addition to individual items.... [This is] the basic structure of an RSS 2.0 feed. Source: Powers, 2008, p. 323 News Readers-Feed Readers-Aggregators A News Reader, Feed Reader, or Aggregator provides an interface that displays the feeds as readable text and organizes the feeds by their source (Chen & Bøen, 2008, p. 321). There are plenty of 3

4 options when choosing a feed reader. An aggregator application may be: (a) a standalone product such as RSSreader, that displays the content much like Microsoft Outlook; (b) combined with a Web site, examples are My Yahoo!, Google Reader, and Bloglines; (c) a plugin, such as Mozilla Firefox s Live Bookmarks, which is an add-in component to your Internet browser; or (d) a podcatcher a program that captures multimedia feeds (also known as podcasts). itunes and smartfeed are two examples of podcatchers (Descey, 2004, p. 5; Castro, 2007, p. 377). In the end, it does not matter which aggregator an individual prefers, but rather, it is the versatile, low-cost, convenient, and customizable aspects of the format s output that has led people and libraries to adopt and utilize this type of information dissemination. Library Awareness Services Initially it was large media companies and conglomerates that were the first to publish automated content. RSS became popular for receiving news stories, weather forecasts, and entertainment features. A 2005 study (Figure 2) shows the type of information pulled by aware RSS users users that knew what RSS technology was, and were aware it was being utilized: Figure 2. RSS content accessed in Source: Grossnickle, 2005, p. 3 4

5 Today, however, RSS is used by almost every type of institution as a way to publish their own authored content, and to distribute third-party content. Libraries use RSS to promote everything from blog entries, to job searches, to health and scientific information, to book chapters 2 and much more depending on the mission of the particular library. Many library Web sites not only post RSS feeds, but they also post detailed instruction on how and why to use them. Libraries will also recommend subscribing to podcasts in order to distribute audio and video content such as audio books, storytelling, guest lecturers, virtual tours, and other recorded events. Rethlefsen, Mojon, and Rothman, authors of Internet cool tools for physicians, promote the use of feeds and RSS management tools in the medical library setting as a way of adding value to information sources. Since physicians have busy schedules, and their information need is highly dependant on the most current research, many doctors use RSS feeds initiated from within a medical database such as PubMed, MedWorm, MEDLINE and others to gain the latest information. The authors further demonstrate how RSS tools can add value to information by not only providing dozens of options for managing hundreds of feeds, but also by linking the feeds directly to the full-text articles or having them sent to an account. This saves a physician time by not having to go to the library, where he or she must flip through the table of contents of multiple journals in order to find the topics relevant to their practice (2009, p. 78). RSS Management Filtering is the next step after aggregation (Chen & Bøen, 2008, p. 321). Often times, dozens of feeds covering hundreds of topics are displayed in one place such as a personalized homepage. In order to manage information overload, techies and librarians recommend using cool tools like Yahoo! Pipes, and Google Reader along with OPML (Outline Processor Markup Language) files. These and many other applications can bundle, filter, translate, and prioritize a large number of feeds. There is now even an RSS interface agent called Fido. Fido is an application that lets the consumer interact and provide feedback to his or her subscriptions by allowing consumers to rank chosen keywords (<items>) within the text of the feed. The program compares the user s ranking with their user profile providing more relevance in the feeds that are displayed. In other words, Fido is a product that uses semantics and 5

6 algorithms to work with an individual s current interests and priorities. Chen and Bøen state that this is an example of the next generation of feed readers (2008, p. 321). Conclusion In general, library services exist to lead people to information. Whether it is a picture, an article, a seminar, or a blog, the quantity of information being published on the Web is ever-increasing and overwhelming. In addition, the simultaneous demise of traditional newspapers 3 is reason enough for libraries to find ways of keeping its constituents abreast of the news. However, libraries are not just serving up news, they are serving up information, which is what they were established to do. Like the common goal of many organizations, libraries are supposed to get the right information, to the right person, at the right time, and they can do so more effectively by implementing and supporting 21 st century information-retrieval practices. Since RSS and Atom 4 are arguably the most widely used XML formats in the world (Yee, 2008, p. 77), they are extremely accessible and can help organize and enhance information services. RSS is simple, cheap, customizable, and timely qualities that are in line with library budgets and objectives. In short, RSS helps to leverage a library s assets, goals, and mission statements by utilizing the connectedness of the Web (Hunter et al., 2004, p. 481), a movement toward Library

7 References Castro, E. (2007). HTML, XHTML, & CSS: Visual QuickStart Guide (6 th ed.). Berkeley, CA: Peachpit Press. Chen, W. & Bøen, T. (2008). A personalized RSS news filtering agent. In Ellis, R., Allen, T., & Petridis, M. (Eds.), Applications and innovations in intelligent systems XV: Proceedings of AI-2007, the twenty-seventh SGAI international conference on innovative techniques and applications of artificial intelligence (pp ). London, UK: Springer. Descey, D. (2004). All aboard the Internet: Your one stop for news and information! [Electronic version]. TechTrends, 49(3), 4 6. Grossnickle, J., Board, T., Pickens, B., & Bellmont, M. (2005). RSS crossing into the mainstream. Retrieved February 15, 2009 from publisher.yahoo.com/rss/rss_whitepaper1004.pdf. Hunter, D., Watt, A., Rafter, J., Duckett, J., Ayers, D., Chase, N., Fawcett, J., Gaven, T. & Patterson, B. (2004). Beginning XML (3 rd ed.). Indianapolis, IN: Wiley Publishing, Inc. Morris, T., Tomasi, C. & Terra, E. (2008). Podcasting for Dummies (2 nd ed.). Hoboken, NJ: Wiley Publishing, Inc. Powers, D. (2008). PHP object-oriented solutions. Berkeley, CA: Friends of ED/Apress. Rethlefsen, M., Mojon, D.S. & Rothman, D. (2009). Internet coot tools for physicians. Verlag Berlin Heidelberg: Springer. Yee, R. (2008). Pro Web 2.0 mashups: Remixing data and Web services. Berkeley, CA: Apress, Inc. Retrieved January 8, 2009 from /?p= d31ff4a228836e45ad &pi=8. 7

8 Notes 1 The company is now known as Apple, Inc., but at that point in time it was Apple Computer, Inc. 2 The Web site DailyLit offers subscriptions to one book chapter at a time via a feed reader or an account. 3 For a great discussion about Web content and the future of newspapers see the February 11, 2009 episode of Charlie Rose. Available at 4 The name Atom applies to two related proposed standards: the Atom Syndication Format (whose current version is also known as Atom 1.0) and the Atom Publication Protocol (APP).... Designed to overcome perceived shortcomings of the various RSS formats, Atom 1.0 is currently a proposed IETF [Internet Engineering Task Force] standard: Atom 1.0, constructed to syndicate web content, has a similar semantics to RSS but a different naming scheme. In an Atom document, a <feed> element is composed of one or more <entry> elements, each described by a set of tags such as <title>, <link>, <id>, and <summary> (Yee, 2008, p. 82). Atom 1.0 is the default format for Flickr feeds; it is natively able to encode much of the information for which Media RSS is being used in RSS 2.0. The Atom feed does, however, use a Dublin Core extension to mark up a date (Yee, 2008, pp. 87, 90). 8