A quick comparison of ‘compare products’ functions, I’m particularly interested in the use of screen space and comparing several products. Yahoo shopping will let you compare a seemingly unlimited number of products in its columnar layout, so the visual scanning is done by horizontally scrolling. Same deal at NexTag and EspressoPeople. Dealtime also lets you select many items but paginates the results, five per page. Bizrate uses a pop-up alert when you try to select more than three items. MySimon compares prices, not features, and uses rows instead of columns. Canon UK offers three pull-down menus displayed horizontally and each column is populated dynamically (neat, if limited). Turbo Tourney just displays their three products, no interaction needed.

Holy crap, check out the Yahoo Shopping SmartSort. The interaction design – especially the most/least important radio buttons – is a little confusing, but it’s fast and useful. Neatest of all is the copy for each of the items, which changes dynamically, so it can say things a person would say, like

Toshiba Portege 2010 is a subcompact notebook. It is ranked first because it has the best Screen Size compared to the others in your top 10 results. This Notebook Computer is cheaper than Toshiba Portege R100 which is displayed next.

Algorithmically, that’s

Toshiba Portege 2010 is a [productType]. It is ranked [rank] because it has the best [strongestFeatureByUserWeight] compared to the others in your top [resultSetAmount] results. This Notebook Computer is cheaper than [nameOfNextItem] which is displayed next.

Click one of those radio buttons and the results resort and the copy changes accordingly. I’d love to see the look on the programmer’s face when the designer proposed this.