Usability by Hand, AJAX and Efficiency
Posted on April 5th, 2006 in Usability | 2 Comments »
“Take drag and drop shopping carts, where you drag product in or out of the space reserved for your cart. This sure looks fancy. But, it is more than 1000% slower to drag and drop, than to simply click an “Add to Shopping Cart” button. Specifically it takes 0.2 seconds to click on any target, and 2.4 seconds to drag and drop.” (Author: Thoman Baekal)
2 Responses
Where do the 0.2/2.4 seconds come from? Nielsen? The problem isn’t with how long it (usually) takes to add something to your shopping cart, it’s that when you do, the “items in your cart” page appears, then you have to “return to shopping” or something like that. To me, that’s wasted time *and* a disruption of flow.
If you can drag items to a sidebar, where they can all be shown without taking you away from the shopping page, then I would happily spend the extra 2.2 seconds. Of course the sidebar-cart could be used with the regular click-to-add method, so I have either shot down my own argument or given Amazon a great idea (where’s my patent attorney?).
Dave,
Good questions about the timing. It can be answered by Fitt’s, which Baekdal references in his article. Here are some resources.
Fitt’s Law Overview
http://www.asktog.com/basics/firstPrinciples.html#fittsLaw
Fitt’s Law Math
http://ei.cs.vt.edu/~cs5724/g1/glance.html
Useful: Fitt’s, GOMS, Use Modelling
http://www-static.cc.gatech.edu/classes/cs6751_97_winter/Topics/user-model/