If you have important information that the people using your site may want to directly link to, state is important as these people will need a URL.  Link >>

Thomas VanderWal checks in with an interesting essay on “state”. 

What is state on the the web?  The definition at WebPedia is:

(n.) The last-known or current status of an application or a process. The terms maintaining state and/or managing state refer to keeping track of the condition of the process.

The Internet is intrinsically stateless because each request for a new Web page is processed without any knowledge of previous pages requested. This is one of the chief drawbacks to the HTTP protocol. Because maintaining state is extremely useful, programmers have developed a number of techniques to add state to the World Wide Web. These include server APIs, such as NSAPI and ISAPI, and the use of cookies.

For the less-technically inclined, you experience the “Statelessness” of the web when you perform an action, then click a link button, wait for a new page to load, then click a link or button, wait for the page to load, etc.  Ever lose data in a form you filled out by clicking the “back” button to go back to the form?  That’s statelessness at work.

For example, compare zooming in on or moving around on a map at Mapquest vs. Google Maps.  Mapquest’s zooms and moves each require a refresh of the page with a new map graphic.

Note how much faster you can zoom and move around with Google.  Click and drag to move, and it’s like you have the whole map already loaded, no waiting for the next chunk to download.

Now watch the URL field in your browser on both mapping services.  On Mapquest, each refresh of the page also loads a new URL that defines the view you’re currently looking at.  Sending the map to a friend, or linking to the map via a web page is no problem - just cut and paste the URL.

Now back to Google - the URL never changes.  In order to send the Google map to a friend you have to note the “Email” link, which puts a specific URL into a new message for you.

VanderWals point is that state, or those those intermediate steps / chunks / pages are important and shouldn’t be “programmed over” without careful forethought and user testing.