Usability

**Usability**
"Usability is about human behavior. It recognizes that humans are lazy, get emotional, are not interested in putting a lot of effort into, say, getting a credit card and generally prefer things that are easy to do vs. those that are hard to do."

//-- David McQuillen in "Taking Usability Offline" Darwin Magazine, June 2003//

Usability is a quality that assesses or improves how easy an interface is to use. This idea is extremely important to user-centered design. It basicly evaluates how efficient, effective, and satisfying the product was for the users. It is defined by:

//Example//: A remote control is a good example of good learnability. All the most-used button are labeled very clearly. The up and down buttons for changing channels are labeled for channels, and the buttons changing volume is labeled for volume. One doesn't need to look up in the menu to figure out how the remote control works (at least for the basic function). **efficiency**: how quickly the user can perform after they have learned the design, //Example:// When the user figures out how to use the remote control, they could use it without thinking. Everything becomes obvious and this leads to efficiency. //Example//: All the buttons on the remote control are organized or mapped out in the most obvious, common or logical way. Some buttons (like up and down button for volume) have different shape than others, making them stand out and easy to find. All of this help to make the remote control very memorable, sometimes to the extent that we don't even have to look at the remote control and we can still change channel. Our fingers remembers by itself the places of each button. //Example:// There are no serious errors you can make with the remote control. The worst thing you can do is turn off the TV (though this could be horrible if you are in the middle of a very exciting show). This is a comforting fact, because you know you can't break anything if you did something weird with the remote control. //Example:// It is a very satisfying experience to use the remote control. You can change the channel while lying on your couch, and you have total control in your hand. ([|http://www.usability.gov)]
 * learnability**: the measure how easily and quickly does the user figure out how to use the product.
 * memorability**: after prolonged in-use, how quickly will the user reestablish proficiency.
 * errors**: how many errors users make, and how serious the errors are
 * satisfaction**: how pleasant it is to use.

Debra Mayhew's "The Usability Engineering Lifecycle" ( Morgan Kaufmann Publishers, Inc.,1999) advocates a solid process for usability success:

1) Define what is need to be done to make the interphase usable 2) Set usability goals 3) Identify the kind of constraints that this platform may have 4) Rethink and re-engineer how the user is currently doing their task 5) Design and do a mock up conceptual models 6) Define screen design standards and make prototypes 7) Develop a style guide 8) Develop a detailed interface design 9) Evaluate the design

Here is a very good article [|"The End of Usability Culture"] provided by the [|digital web magazine] gives a critical view on designers over stress on usability.

Reference: Eaton, Eric. DesignWhys: Designing Web Site Interface Elements (Rockport Publishers, Inc., Massachusetts, 2003) Shilwant, Shailesh, and Amy Haggarty. "Usability Testing for E-Learning." Aug. 2005. 5 Oct. 2007 <[|http://www.clomedia.com/content/templates/clo_article.asp?articleid=1049&zoneid=71>.] "The Bug-Eyed Chronicles: Usability and Leanability." 6 Oct. 2007 <[|http://www.bugeyed.me.uk/2007/08/usability-and-learnability.html>.] "UPA Resources: About Usability." __UPA__. 5 Oct. 2007 <[|http://www.upassoc.org/usability_resources/about_usability/index.html>.]