As information resources grow exponentially, there became the need for identification and persistent longevity of information resources on the Web. This has propelled researchers to begin to devise a means to connect, locate and identify information resources. Because identifying digital content items is one of the most significant concerns in the digital content market (Allison et al. 2005). However, papers published in the faked and predatory journals are lost while in many universities, they are not considered as valuable papers. Moreover, some universities, research institutes, and ministry of education have blacklisted those scientific journals (Tiliute, 2016). Tiliute also noted that almost all open access journals with an assigned DOI have good reputation and those that did not have DOIs are divided into respectable and less respectable. As digital object identifiers have gained prominence in the digital world; it is therefore necessary to study their use in accessing online scholarly materials, especially in Africa.
Uniform Resource Locator (URL)
The most common and familiar identifier on the Web is a Uniform Resource Locator (URL) which make available the location of resources (Boudry and Chartron, 2017). URLs tie Internet resources to their current network location and file (Lawrence et al. 2001). The limitation with URL is that once the document is moved to a new location, the document is lost. As the linking hub for scholarly content, most URLs suffer from link rot and can be created, deleted or changed at any time which eventually leads to problem when trying to cite them (Wass, 2016). Alfred and Edda (2017) affirmed that 44.1% web citation of health sciences online journals in East Africa selected for studies were inaccessible. The findings also show that the average half-life for the URLs cited in journals articles were 10.5years which all generates questions on the value of URLs in accessing scholarly materials. Therefore, a new system of resource identification on the web which is the DOI becomes necessary. However, Feeney (2010) asserted that each DOI is unique and once assigned to an item, remains a constant locator, not changing even as object moves from URL to URL. The DOI for a document is permanent, whereas its location and other metadata may change. Referring to an online document, DOI provides more stable linking than simply referring to it by its URL, because if its URL changes, the publisher need only update the metadata for the DOI to link to the new URL (Witten, Bainbridge and David, 2010).
Understanding Digital Object Identifier
DOI system was developed by International DOI Foundation, with the aim to provide a framework for managing intellectual content, link customers with publishers, facilitate electronic commerce, and enable automated copyright management (Tiliute, 2016). A digital object identifier (DOI) is a character string used to uniquely identify an electronic document or other object. DOI is a tool for the location and identification of digital information published on the Internet. It is an advanced tool that provides unique identification or permanent links to identify specific journal articles and other information resources on the web. The DOI is typically located on the first page of an electronic document near the copyright notice and on the database landing page for the document (America Psychological Association, 2018). Developed by a group of international publishers, the DOI system provides a way to guarantee that digital copies of articles can remain accessible even if a journal changes its domain name or ceases publishing (Hume-Pratuch, 2014).
Digital object identifiers have been compared to barcodes because they are persistent identifiers that catalog content and track movement (Ye, 2007). DOI is specifically in online contents. The contents that have been identified by DOI so far are journals and journal articles, books and book chapters, conference proceedings, technical reports, working papers, preprints, standards, theses and dissertations, components (e.g. graphs, figures) and reviews (CrossRef, 2017). Higgins (2017) noted that the versatility of DOIs means they can be assigned to journal articles, datasets, supplemental material and addendum; to audio, video, streaming media, and 3D objects; to theses, dissertations, technical reports, visualizations and to pre-prints of articles. Even though that the DOI system does not provide a central search capability as stressed by Tiliute (2016), most web search engines will show DOI names in the results of a search by title, by name, or by topic or related terms, while the reverse will also work.
In another development, DOls as a tool can be employed in some studies relating to Altmetrics and Bibliometric (Hausten, Costal, and Lariviere, 2015). Altmetrics are social web metrics for academic publications incorporating a number of variables like downloads, view count, and comments, so as to measure the impact of articles (Galligan and Dyas-Correia, 2013). Kasdorf (2012) opine that it is high time to make DOIs as indispensable to scholarly books, conference proceedings, reports, and datasets as they are to journals. More so, that citation counts and citation metrics are increasingly depending on DOIs, hence scholarly materials that do not have DOIs can be ignored by the systems which generate these important metrics. Thereby, giving rise to underestimation of the impact of such academic publication. Interestingly, all major publications within any given scientific field now use a digital identifier which is DOI for each electronic published document noticed either on the electronic version of the paper either on the printed version or both (Tiliute, 2016).
Unique set of functionalities provided by DOI system and Benefits of implementing the DOI systems as mentioned by International DOI Foundation (2015) are:
Persistence, if material is moved, rearranged, or bookmarked;
Interoperability with other data from other sources;
Extensibility by adding new features and services through management of groups of DOI names;
Single management of data for...