An expert review is a quick way to identify opportunities for improvement in your product's design. I base the review on my experience with many other design efforts and hundreds of usability tests, as well as usability heuristics.

Usability testing involves having your customers interact directly with your product (or a prototype of it). It identifies where your customers might encounter problems with the current design. Can they set it up and use it easiliy? Can they complete the tasks the product was intended to support? Can they find what they're looking for?