Hypertext links embedded into web documents serve several purposes.  They facilitate access to text-based and multimedia Internet resources within a single Web document, from a particular site, or those located at various sites.  Hypertext links can also highlight footnotes, provide access to support materials, define terms, and clarify concepts.

   A HTML hypertext link is created with the tag <A HREF = "xxxxx">.  The text associated with the tag becomes the physical link to other resources or documents.  This association between hypertext on a Web page and particular resource is also referred to as a hypertext reference.  The following is an example of how a hypertext reference is created using HTML: 

       <A HREF="/eric/papers.html">Eric's Papers</A>

   The words Eric's Papers are associated with the Web document papers.html in the directory eric.  

Pathnames

   Pathnames refer to the logical directory path and filename used when creating a link browser uses to locate the resource.  

   A Relative Pathname is used for linking to resource resides on the same server, in the same directory, or in a subdirectory relative to document currently being viewed.  The access protocol, directory path, etc. is based on the Uniform Resource Locator (URL) used to reach the current document. 

   The use of relative pathnames in this document eliminates the need to add http://bones.med.ohio-state.edu/eric/papers/primer/ to every link. Since the majority of the references are relative to the table of contents page, moving this paper to another site or directory will require little to no editing of the links. 

   Here is an example of a link using a relative pathname:

             <A HREF="url.html">URLs</A>

   Absolute Pathnames are used when making reference to documents which are not directly related.  The entire directory structure needs to be present.  They are used when creating links  to resources located elsewhere on a server or elsewhere on the Internet.   Here are two examples of an absolute pathname, one referring to the local server the other to a remote:

Copyright Concerns

   The whole concept of the web is based on the premise of creating connectivity, or hyperlinks, from one document on the Web to others.  The ability to create links to ease customer access to Internet resources is the primary reason libraries create web sites.  A few high profile court cases involving commercial content created a common misconception that copyright law requires a librarian to seek and obtain permission before adding a link to existing content.  This is not the case.

   A Uniform Resources Locator (URL) from which hyperlinks are formed is considered to be informational content, much like a phone number or street address.  Much like phone book producers or a mail order companies do not need to ask permission from a homeowner to sell phone numbers and addresses to othercompanies, web authors are not required by copyright law to ask permission to use a URL in the creation of a link.  Another way to look at this is that authors of scholarly research are not bound by copyright to contact authors of the articles they cite to request their permission to cite them.  Similarly, web authors are not required by copyright law to ask permission to cite an existing link.

Next:
URLs

Back:
HTML