7.2 - Usability

Usability

The extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency, and satisfaction in a specified context of use.

Ease of use

Novice users of a product can learn its features within one or two hours. 

Intuitive

Using or based on what one feels to be true even without conscious reason. E.g. pushing buttons, turning knobs, etc.

Mapping

Correspondence between the layout of the controls and their required action. E.g. stovetop, xbox controller, etc.

Visibility

Controls should have high visibility and be obvious how they work. E.g lights turn on when in use, colors, symbols, etc.

Low memory burden

User does not need to have to memorize many features to use it. Fusion 360 = High memory burden, Netflix = low memory burden

Constraints

Ways that limit the way a product can be used. E.g. USB in a USB slot, chatGPT prompts stopping explicit content, etc.

Affordance

Property of an object that indicates how it can be used. Buttons afford pushing, knobs afford twisting/turning. 

Learnability

The extent to which a user can operate a product or system at a defined level of competence after a pre-determined period of training.  

Attitude

Perception, feeling, and opinions, about a product by a user. 

Efficiency of use

How quickly and easily a user can complete tasks with a product, system, or interface. A design with high efficiency minimizes wasted effort, time, and steps, allowing users to achieve their goals smoothly.

Effectiveness

A measure of the speed of performance or error rate and its reflection to the capabilities of a product. 

Clean unambiguous feedback

Lights turn on when a product is on.

Clear human interface

The point where humans and machines interact.

User error

Mistakes/slips when using the product due to aspects such as complexity. 

Benefits from enhanced usability

Improves product acceptance, improves user experience, improved user productivity, reduces need for training and support. 

Population stereotypes

Categorisation of populations based on culture, class, gender, etc. Assumptions and associations can be made in how a population may approach a given situation.