500-word summary on Persistent URLs and Citations

TO: Prof. Ellis

FROM: Alex Cheung

DATE: Oct. 6, 2021

SUBJECT: 500-Word Summary of Article About Persistent URLs and Citations

Persistent URLs and Citations are one of the most important elements of an article, scholarly paper, or any academic writing. These persistent URLs provide a link to a full-text article that will never change thus always linking to the article that is a part of a database or journal. Without them, it might be hard to find that specific full-text article later down the road and. Nicholas Homenda believes that persistent URLs and citations are a necessity as evident by his thought, “As libraries, archives, and museums make unique digital collections openly available via digital library platforms, they expose these resources to users who may wish to cite them” [1, p. 1].

There are four main methods used for persistent URLs that include: Handle, DOI, ARK, and PURL. As libraries, archives, and museums move more of their collections to digital mediums, having a persistent URL to access these materials are essential to find the said material which is part of certain collections [1, p. 1]. Most of these persistent URL services have been around since the 1990s to the early 2000s [1, p. 2]. Each site uses their own version of persistent URLs thus resulting in many different types of links. This calls for more standards for persistent URLs.

There is a term called “link rot” which means that overtime the link will eventually not point to the page or file that it was meant to point to. There have been several studies done on link rot by tracking the availability of the resource over time [1, p. 3]. In recent works by Koster, he mentions that the persistent URL method that appears the most often in literature is the Digital Object Identifier (DOI) [1, p. 4]. 

For over 20 years, persistent URLs have been providing persistent links to digital objects allowing users worldwide to access the content [1, p. 4]. Persistent URLs are even used to create permanent links to government information. This was an early effort by the Cendi Persistent Identification Task Group to implement the Federal Enterprise Architecture (FEA) and a theoretical Federal Persistent Identification Resolver [1, p. 4].

All persistent links should ideally be accessible via URLs that will outlast the information that it is linking to unless that link is subjected to “link rot” [1, p. 4]. In one investigation into “link rot” on information from Medline abstracts from the years 1994-2006, shows that about 20% of the links were dead in 2008. The topic of “link rot” has been discussed as early as 2003 in a book by Markwell and Brooke named ““Broken Links: Just How Rapidly Do Science Education Hyperlinks Go Extinct”, which is cited by many link rot studies but it looks like this too has suffered from link rot in works that cited this book [1, p.4]. 

In a recent study, they tried to locate digital collections that met the following criteria:

  1. Openly available
  2. Part of a repository service
  3. Gathered as part of a site or service that contains multiple collections
  4. Unique to an institution but not duplicated or licensed content

With these criteria in place, it helps to find unique and publicly available digital collections [1, p. 5]. The study found that the DLF institution had 171 out of 197 member institutions that had accessible digital collections, while only 153 out of the 171 met the criteria for this study [1, p. 6]. 


[1] Homenda, N. (2021) ‘Persistent URLs and Citations Offered for Digital Objects by Digital Libraries’, Information Technology & Libraries, 40(2), pp. 1–12. doi: 10.6017/ital.v40i2.12987.

1 thought on “500-word summary on Persistent URLs and Citations”

  1. 500-word summary on how the Escalator forever changed our sense of space

    To: Prof. Ellis
    From: Gani Graceni
    Date: 12/22/2021
    Subject: 500 – Words summary

    This is a 500-word or close to 500-word summary of an article that describes the invention of the escalator, the evolution from the first revision and the impact it had in the world of mass transportation and shopping industry.

    [1] Before the escalator was invented the only way of transporting people or material was done via steps or elevator which are both very limited in many different aspects. It is clear that the pre-escalator era was calling for something innovative. According to the Author of this article with the invention of the escalator “Neither the sky nor the ground would be the limit”.

    [2]The article explains that the moving staircase was a 19th century invention and came out at the time “aspirin”, came out and evolved to what we call an escalator these days.]The author gives credit to the inventor “Charles Seeberger who came up with the moving stair case version and explains that this system would forever change the way people move, the way of people shop, the way how buildings are constructed.

    [3]The article gives a lot of credit to the next revision of the “improvement stairs”, by patent issued engineer Nathan Ames. Unfortunately his version did not get as much attention and never made it as a product. At the same time population grew in the metropolitan areas, building and shopping malls needed way of transporting in mass so other versions of the moving stairs were being developed. Finally another engineer whose name was Jesse Reno came up with a much more improved version and made use of the linear belt using an electric motor he came as close as you can get to a modern day escalator.

    [4] In this article the escalator design shows the step by step process of evolving from one design to another and the key switch is in this process was the advertising strategy that the main manufacturers did use. At busiest times of shopping and the expanded market the need for a solid escalator design was based on the best advertisement strategies along with the team of engineers working for the next generation of the escalator.

    [5]According to the article this type of system was granted a patent in 1892 as an “Inclined Elevator”. There was a show that took place in Coney Island and one of these systems was installed at high scale infrastructures such as the Brooklyn Bridge. Very soon another inventor as per the article came up with a much improved escalator which is very similar to what we have now days in terrain. The inventors name was Geroge Wheeler whose patent was bought by Charles Seeberger who was signed by the Elevator giant “Otis Elevator” and from then escalators became part of our life.

    S. Magazine, “How the escalator forever changed our sense of space,” Smithsonian.com, 27-Jun-2019. [Online]. Available: https://www.smithsonianmag.com/innovation/how-escalator-forever-changed-our-sense-space-180972468/. [Accessed: 22-Dec-2021].

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