

Home Articles Making URLs Predictable	Articles About KB

Making URLs Predictable

by Kristoffer Bohmann, July 9, 2000

URLs that are easy to predict make it easier for users to type in a URL and link to pages.

URL Redesign

URLs for articles at Bohmann.dk was recently changed from URLs using date-based file names to URLs using title-based file names. Examples from two articles show the difference between the two types of file names:

Calculating Usability Effects (July 6, 2000)
Old URL by date: http://www.bohmann.dk/articles/2000jul06.html
New URL by title: http://www.bohmann.dk/articles/calculating_usability_effects.html
Ways to Shop the Web (June 11, 2000)
Old URL by date: http://www.bohmann.dk/articles/2000jun11.html
New URL by title: http://www.bohmann.dk/articles/ways_to_shop_the_web.html

Usability Heuristics

Proven usability heuristics were used to evaluate the change. Four of ten usability heuristics were relevant in this case:

Match between system and the real world: The system should speak the users' language, with words, phrases and concepts familiar to the user, rather than system-oriented terms. Follow real-world conventions, making information appear in a natural and logical order.
Recognition rather than recall: Make objects, actions, and options visible. The user should not have to remember information from one part of the dialogue to another. Instructions for use of the system should be visible or easily retrievable whenever appropriate.
Flexibility and efficiency of use: Accelerators -- unseen by the novice user -- may often speed up the interaction for the expert user such that the system can cater to both inexperienced and experienced users. Allow users to tailor frequent actions.
Aesthetic and minimalist design: Dialogues should not contain information which is irrelevant or rarely needed. Every extra unit of information in a dialogue competes with the relevant units of information and diminishes their relative visibility.

Match between system and the real world

Before the change, URLs to article pages were already written in plain language language as no computer codes were used. However, dates were used as file names. And file names written as dates are somehow system-oriented terms. Dates contain numbers used by computers and editors to keep track of many pages. Also, dates are written in different formats (6-jul 2000, 6/7/2000, etc.)

On the other hand, file names written as titles use plain language. Users have a better memory for file names written in plain language than file names written as date code. It is easier to comprehend and remember the file name calculating_usability_effects.html than 2000jul06.html.

Recognition rather than recall

Most URLs on the Web are difficult to remember. The purpose of title-based URLs is to help users predict the URL based on the article title. Not making URLs recallable. Users are more likely to remember simple headlines than a date. Especially as they revisit websites, which most users do several times.

Flexibility and efficiency of use

User performance is often accelerated through site information structure that fits the users model of the world. The accelerator effect is created more by the information structure and less by the file name per se. Expert/repeat users only need the exact article title to link to an article or to go to it using a browser. These users already know that:

www.bohmann.dk/articles/ is the location for articles at Bohmann.dk.
.html is the extension of all files at the site (not .htm).
Small letters are used for all URLs at the site, never capitalized letters.
The underscore symbol (_) is used to separate words in new article titles.

This technique grows even more important when Web services offer affiliate programs. Their affiliates need a simple way to link to products using a standardized URL. For instance, I link to books at Amazon.com Books using this URL:

http://www.amazon.com/exec/obidos/ASIN/999999999/onlineusability
(999999999 is the ISBN number, onlineusability is my Affiliate ID)

Affiliates can setup such links without even going to the Amazon site. Simple URLs may actually generate sales.

Aesthetic and minimalist design

Titles provide information about what a page is about. So, titles are far more informative than dates. This supports title-based URLs.

Newness Biased Users

Using dates has yet another dimension. Users, and online news readers in particular, tend to prefer new content to old content. If users need to choose between two similar articles, where one was published yesterday and one published last year, they are very likely to go to the newest article.

I suspect users believe that "new" equals "more updated" and therefore of higher quality. This is unfortunate for content aggregating sites who also want their users to approach "old" content. Title-based file names help deemphasize the importance of page age. Meanwhile, the value of older content is improved simply because less attention is drawn to the date.

Don't get me wrong. Dates are still important if you want a site to present a flow of information. But I don't believe this information should not be put in the URL. Publishing dates can also be presented at homepages, overview pages, or on top of the page.

About the Author
Kristoffer Bohmann (biography) M.Sc. thinks and writes about high-quality user experiences. His philosophy: Users first. You can contact him at kristoffer@bohmann.dk.