Sunday, November 23, 2008

Problems with URLs

Problems with URLs

The primary problem with URLs is that they define location rather than meaning. In other words, URLs specify where something is located on the Web, not what it is or what it’s about. This might not seem to be a big deal, but it is. This issue becomes obvious when the problems with URLs are enumerated;

URLs aren’t persistent. Documents move around, servers change names, and documents might eventually be deleted. This is the nature of the Web, and the reason why the 404 Not Found message is so common. When users hit a broken link, they might be at a loss to determine what happened to the document and how to locate its new home. Wouldn’t it be nice, if no matter what happened, a unique identifier indicated where to get a copy of the information?

URLs are often long and confusing. People often have to transcribe addresses. For example, the following is quite a lot to type, read to someone, or avoid not breaking across lines in an email;

Firms are already scrambling for short domain names and paths to improve the typability of URLs, and most folks tend to omit the protocol when discussing things. Despite these minor clean-ups, many URLs are very long and “dirty,” filled with all sort of special characters.

URLs create an artificial bottleneck and extreme reliance on DNS services by specifying location rather than meaning. For example, the text of the HTML 4.01 specification is useful document and certainly has an address at the W3C Web site. But does it live in other places on the Internet? It probably is minored in a variety of locations, but what happens if the W3C server is unreachable, or DNS services fail to resolve the host? In this case, the resource is unreachable. URLs create a point source for information. Rather than trying to find a particular document, wherever it might be on the Internet, Web users try to go to a particular location. Rather than talking about where something is, Web users should try and talk about what that something is.