Glossary » Usability Methods
mythical man-month
a man-month is a way of measuring work output for production which is reasonably helpful in certain limited areas of industries like manufacturing. The basic idea is that if you want to produce twice as many sprockets, then you can…
Read more »NGOMSL
Natural GOMS Language. NGOMSL was developed as a formally defined version of CMN-GOMS based on cognitive complexity theory (CCT). It has a more structured hierarchy than CMN-GOMS and a well-defined analysis methodology for developing models. In addition to the execution…
Read more »NOIR
nominal-ordinal-interval-ratio. A mnemonic for remembering common data scales used in empirical measurement.
Nominal – a set of items that can be distinguished by name or category. Ordinal – items that can be ordered, such as military rank, or units of…
Read more »object relationship matrix
a technique for organizing the objects in an application and establishing links between them. All the primary objects in the application are listed along both axes of the matrix, and their relationship is described in each cell of the matrix.…
Read more »objects-and-actions design methodology
an approach to interface design based on analyzing the task domain: determine what data (objects) needs to be manipulated and what functions (actions) can be performed on that data without consideration of how the interface needs to look or behave.…
Read more »observation room
during usability testing, the observation room is a separate room from which experimenters can observe the user without disturbing the user, often observing through a video connection or through a one-way mirror. The observation is almost always explicit — the…
Read more »observational study
watching people’s behavior to find patterns and design-relevant activities. For instance, observing people working in an office environment to determine their work processes and computer usage patterns.
Casual observation can be used to gain a basic understanding of a situation…
Read more »one-way mirror
a piece of glass that is mirrored from one side but can be seen through from the other side, sometimes used in user testing or focus groups so that observers may watch the session without being distracting or disruptive.
Read more »open card sort
a type of card sort that asks users to suggest categories that topics group into. Users are provided with a list of topics (e.g. content pieces to go on a website) and are asked to group them and to label…
Read more »paper-and-pencil prototype
a paper sketch of a user interface with enough detail to make design decisions and usability evaluations, whether through a usability inspection, a focus group, or a simple user test.
Read more »parallel design
two or more separate design groups create design proposals independently and then come together to compare ideas before committing to a single design approach. This is similar to brainstorming techniques that encourage independent idea generation in order to come up…
Read more »participant observation
observing people by joining them in their activity, e.g. working with people in their workplace to see how they use an office computer system, playing games at the arcade with other game players, or joining a programming team to understand…
Read more »participatory design
a democratic approach to design that encourages participation in the design process by a wide variety of stakeholders, such as: designers, developers, management, users, customers, salespeople, distributors, etc. The approach stresses making users not simply the subjects of user testing,…
Read more »persona
a description of a specific person who is a target user of a system being designed, providing demographic information, needs, preferences, biographical information, and a photo or illustration. Typically, multiple personas are developed in the early stages of design that…
Read more »PERT chart
(Program Evaluation and Review Technique) a type of flowchart used in project management, where each task is represented by a node and connected to other tasks with arrows to indicate task dependencies. Each node may be labeled with necessary resources…
Read more »pervasive usability
a principle of design that advocates the application of usability methods in every stage of the design process. Some of the primary stages of design, and some example usability techniques, are:
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requirements gathering: field studies, interviews, focus groups
requirements
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Read more »pilot test
or formative test; an initial run of a study (e.g. an experiment, survey, or interview) for the purpose of verifying that the test itself is well-formulated. For instance, a colleague or friend can be asked to participate in a user…
Read more »playtesting
testing of games (including usability testing), examining pace, flow, narrative, controls, entertainment value, appeal for different target populations, challenge, novelty, etc.
Read more »pluralistic walkthrough
a method of usability inspection where a diverse group of stakeholders in a design are brought together to review the design, including user interface designers, users, developers, and management. The walkthrough is conducted by identifying primary tasks for the system…
Read more »power law of practice
an expression of time to perform a task based on practice trials, saying that people improve in speed at a decaying exponential rate.
Tn = T1 n-a, a ~ 0.4
Tn = the time to perform a task after n…
Read more »prototyping
the development of incomplete representations of a target system for testing purposes and as a way of understanding the difficulties of development and the scale of the problem.
Prototyping is an essential element of an iterative design approach, where designs…
Read more »prototyping theatre
a puppet show approach to prototyping and user testing. User interface elements, such as screens and widgets are held up in the theatre, by hand or with sticks, to demonstrate how the screen works. Multiple puppeteers are needed for complex…
Read more »quality assurance
QA or quality control; ensuring that the results of your processes have high quality, measured my minimization of flaws in design and production and by product success and customer satisfaction. Quality assurance can be implemented throughout a design process (not…
Read more »quality inspection
reviewing a user interface for its conformance to style guidelines and specifications, especially with regard to required functionality and robustness (frequency of system errors) because these have a dramatic effect on usability. The purpose of a quality inspection is to…
Read more »question-asking protocol
in contrast to the think aloud protocol, in which users are asked to speak freely about their thoughts without prompting from the tester, in the question-asking protocol, the tester explicitly asks the user questions during the user testing session, to…
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