Usability

toc =Usability=

Usability can be referred to as, "The effectiveness, efficiency, and satisfaction with which users can achieve tasks in a particular environment of a product. High usability means a system is: easy to learn and remember; efficient, visually pleasing and fun to use; and quick to recover from errors." ([|www.dictionary.com])

There are several guidelines and/or principles designers should follow as they begin to develop their product. A few are:
 * __Visibility-__ Helping users visualize a mental model of the 'thing' identical to that of the designer. It helps in allowing the user correctly predict the outputs effects of thier actions. A user should know what the product is capable of by simply glancing at it.
 * Mapping- Mapping refers to the relationship between physical controls and the actions they perform.
 * __Feedback-__ By giving immediate feedback to a user, he or she will be able to easily navigate around a product. It will be easier to learn thus giving the user great satisfaction.
 * __Memory Load/Memorability-__ The amount of information needed to be remembered should either be minimal or simple to retain. There should be some consistency and relationships to other older or newer elements so it is easy for the user to recognize.
 * __Accessibility-__ Everyone physically, geographically, emotionally, politically, etc. should have access to technology regardless of any natural contrainsts. There should be options for those with disabilities to allow them to be able to use the product effectively and efficiently. For example, having options to change colour schemes, text size, picture quality, language options etc... on a website/computer are ways to make a product accessible. By also making the product available worldwide to all cultures and societies, accessibility is greatly increased.

=Usability Goals=

The usability of a product is very important and it is regarded as to ensuring that the product is easy to learn, effective to use, and enjoyable from the users perspective. In order for a product to work well with its users it should take into consideration six main usability goals. If a product or system incorporates these goals within their designs they are sure to make a user-friendly product that does what is expected of it. Usability can be broken down into 6 goals:


 * **Effectiveness** – this refers to how well a system is doing at what it is supposed to do. If a product does not do what is expected of it, it is basically useless.
 * **Efficiency** – this refers to the way a system or a product actually helps users in carrying out the tasks of the product. If there is a problem with the product there should be a way in letting the user know that something is wrong.
 * **Safety** – ensures that the user is protected from any dangerous conditions such as features of the product that might make it dangerous there should be a mechanism in place that prevents it form happening or warning signs on the product.
 * **Utility**– refers to whether the system gives the user the right kind of functionality so that they can do what they need to do and what is expected of the system. If the system does not do what the user needs or wants it to do it is not very useful.
 * **Learnability** – the system should be relatively easy to learn, learnability refers to how easy it is to learn otherwise known as how "user-friendly" a system or product is. A ten-minute rule can be applied to some technologies.
 * **Memorability** – this refers to after using the system how easy is it to remember how to use. Once you learned it once do you remember it for the rest of your life or do you have to start over again?

Some user experience goals deal with making systems that are satisfying, enjoyable, fun, entertaining, helpful, motivating, aesthetically pleasing, supportive of creativity, rewarding, and emotionally fulfilling (Mike Jones - Lecture Notes).

=Interaction Design vs. Usability Testing=

Two factors central to building usability into products are interaction design and usability testing. Although both deal with concerns of usability, design is a front-end concern, while testing is at the back end. Both practices seek to ensure that the user's experience with the product is consistent with expectations; that the use of the product is intuitive (if this product follows universal design); and that there's no needless obstacle to the successful completion of the tasks.

Interaction design obliges designers to do some requirements planning, and it answers this question: What does the user expect to do while using the product? To be successful, the designer must thoroughly find out the answers, through numerous user studies.

Once the front end can relatively be shown to the users (hi-fi or lo-fi prototypes), formal usability testing can begin. These tests should provide feedbacks to designers to refine the interface further. How much more usability testing to do depends significantly on time and resources. In theory, the more testing you do, the better the product. Nonetheless, after a certain point, diminishing returns "set in and very little that's new is brought to light" (Binstock). It's not to mention that testing consumes a significant portions of time and resources and very few project achieve the goal of testing the product fully thoroughly before release.

=Importance in the Design Process=

Violating the usability goals will most definatly be detrimental in the success of a new product. A great example of this is BMW's flagship sedan, the 7 series. Despite being a technological masterpiece, the latest generation 7 series has created a large amount of controversy because of its lack of usability. Simple functions such as operating the radio or even starting the car has been made significantly more confusing and difficult. Even "prospective purchasers need a 20 minute training session before a test drive, and a further one-hour session if they actually buy one - as well as having three owners manuals to wade through" ([|http://www.usability.uk.com/resources_spoon9.htm).] Due to the lack of usability in the 7 series, this particular market segment is dominated by other manufactures of luxury vehicles. = =

Resources:
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 * Binstock, Andrew. "New Mantra: Usability." __Information Week__. 06 September 1999.
 * [|www.dictionary.com]
 * http://www.usability.uk.com/resources_spoon9.htm
 * __[|http://www.stcsig.org/usability/topics/articles/ucd _web_devel.html#what_is_UCD]__
 * Mike Jones Lecture Notes