Joel Spolsky, the guru behind Joel on Software, has a straightforward and on point definition of usability:

“Something is usable if it behaves exactly as expected.”

By that definition (and just about any other), the beta web search currently available off of Microsoft’s Live.com website isn’t usable. Here’s the problem:

Generally speaking, when I do a search, the first link I click on doesn’t do it. Unless I’m looking for a specific website, searching usually involves clicking on multiple search results links until: (a) I find exactly what I’m looking for, (b) what I’ve learned from the multiple results I’ve clicked on satisfies my research needs or (c) I give up.

So when I search, I have an expectation that when I click the “Back” button the results will appear as they did when I left them. If I’m on the third page of results, I want to see the third page of results when I click back. The Ajax-driven Live.com web search doesn’t meet that expectation. It loses your place.

Here are the search results for “bill gates” (I scrolled into the results a bit):

After I click on the Wikipedia option (result seven), and click back, I get the following. Note that I can no longer get to results 1-5. Those are now gone. Wikipedia is now result two instead of result seven.

If I click on Wikipedia again, and click back, I get this. These are the results I saw on my initial search. So I’m back where I started.

I think in their quest to do something in Ajax and create a fancier interface, the folks behind Live.com lost touch with how people actually use search.