Usability
Usability can be described as the capacity of a system to provide a condition for its users to perform the tasks safely, effectively, and efficiently while enjoying the experience.
[2] The object of use can be a software application, website, book, tool, machine, process, vehicle, or anything a human interacts with.
For example, after observing and interviewing users, the usability expert may identify needed functionality or design flaws that were not anticipated.
According to Jakob Nielsen, "Studies of user behavior on the Web find a low tolerance for difficult designs or slow sites.
Each component may be measured subjectively against criteria, e.g., Principles of User Interface Design, to provide a metric, often expressed as a percentage.
This association between intuitive use and familiarity has since been empirically demonstrated in multiple studies by a range of researchers across the world, and intuitive interaction is accepted in the research community as being use of an interface based on past experience with similar interfaces or something else, often not fully conscious,[11] and sometimes involving a feeling of "magic"[12] since the course of the knowledge itself may not be consciously available to the user .
It therefore addresses technical human factors and ergonomics issues only to the extent necessary to allow managers to understand their relevance and importance in the design process as a whole.
Another more expensive but more insightful method is to have a panel of potential users work closely with the design team from the early stages.
Models are based on psychological principles and experimental studies to determine times for cognitive processing and motor movements.
Cognitive models can be used to improve user interfaces or predict problem errors and pitfalls during the design process.
[23] Keystroke level modeling is essentially a less comprehensive version of GOMS that makes simplifying assumptions in order to reduce calculation time and complexity.
Participants in a card sorting session are asked to organize the content from a Web site in a way that makes sense to them.
Tree testing evaluates the findability and labeling of topics in a site, separate from its navigation controls or visual design.
Prototyping is an attitude and an output, as it is a process for generating and reflecting on tangible ideas by allowing failure to occur early.
This tool kit is a wide library of methods that used the traditional programming language and it is primarily developed for computer programmers.
Observation of the user's behavior, emotions, and difficulties while performing different tasks, often identify areas of improvement for the system.
With a more refined prototype, designers often test effectiveness, efficiency, and subjective satisfaction, by asking the user to complete various tasks.
[26] After conducting usability tests, it is important for a designer to record what was observed, in addition to why such behavior occurred and modify the model according to the results.
Additionally, this style of user testing also provides an opportunity to segment feedback by demographic, attitudinal and behavioral type.
As a widespread method of usability testing, think aloud provides the researchers with the ability to discover what user really think during task performance and completion.
Subjects-in-tandem (also called co-discovery) is the pairing of subjects in a usability test to gather important information on the ease of use of a product.
The approach includes component-specific quantitative measures based on user interaction recorded in log files, and component-based usability questionnaires.
This type of evaluation is very powerful for determining the usability of a device because it combines multiple studies to provide very accurate quantitative support.
Personas are fictitious characters created to represent a site or product's different user types and their associated demographics and technographics.
Personas are the archetypes that represent actual groups of users and their needs, which can be a general description of person, context, or usage scenario.
To gather the marketing data that personas require, several tools can be used, including online surveys, web analytics, customer feedback forms, and usability tests, and interviews with customer-service representatives.
In particular, the benefits fall into several common areas:[35] Increased usability in the workplace fosters several responses from employees: "Workers who enjoy their work do it better, stay longer in the face of temptation, and contribute ideas and enthusiasm to the evolution of enhanced productivity.
Areas of concern in an office environment include (though are not necessarily limited to):[37] By working to improve said factors, corporations can achieve their goals of increased output at lower costs, while potentially creating optimal levels of customer satisfaction.
Anyone who aims to make tools easier to use and more effective for their desired function within the context of work or everyday living can benefit from studying usability principles and guidelines.
For those seeking to extend their training, the User Experience Professionals' Association offers online resources, reference lists, courses, conferences, and local chapter meetings.
