Glossary » Usability Methods

critical incident analysis

critical incidents are events that represent significant failures of a design, such as when a user accidentally unplugs the computer by kicking the power cords under the desk or when a nuclear powerplant goes critical because an operator thought that…

CRUD

create-report-update-delete; a mnemonic for remembering the 4 basic operations in administering a database.

day-in-the-life studies

an approach to observational studies where one person is followed by the observer throughout a typical day and everything they do is recorded in order to get a detailed understanding of their work processes and work environment. By following a…

debriefing

after running a user study, explaining to a participant what happened and what the study is for, explaining any deception used in the study, asking for any remaining comments or concerns, and ensuring that the participant walks away with no…

decision tree analysis

a method for evaluating how users make decisions in performing their tasks. Through interviews and observations, a decision tree is created to model options a user must choose among in performing a task. The decision tree may be developed with…

defect tracking

typically refers to identifying flaws appearing during manufacturing, which in software design normally pertains to the translation from design specs to finished software. The goal is not only to spot defects but to track them and identify the source of…

demand characteristics

a potential problem in user studies where people being studied have a tendency to behave in a way that reacts to what they think is expected of them. In user testing, for instance, people may tend to say an interface…

design for manufacture

a term from industrial design that emphasizes the importance of making tradeoffs so that designs are actually practical to manufacture at reasonable costs, in a reasonable amount of time, given the resources, personnel, and tools available. User interface designers need…

design for yourself

a method of motivating an application’s features and user interface design by building a tool that the designers and/or programmers would use for themselves. This grounds the design in real-world requirements and ensures a rapid feedback loop between making design…

design rationale

the reasoning that leads to design decisions. Documenting design rationale is important for validating that the correct design decision was made, to help those who are trying to interpret ambiguous design decisions or examples that don’t fall clearly within a…

design space analysis

exploring design options and their implications, by considering pros and cons and dependencies between design decisions. Various methods include tradeoff analysis and decision tree analysis.

design-prototype-test cycle

a design process methodology of driving changes in design through successive instantiations of the design that are evaluated through some type of user testing, user feedback, or inspection technique.

1. design – generate ideas, analyze, and create solutions
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designer management

the approach of having the designer of software manage the development project, thus ensuring that design considerations are not inappropriately compromised in the development process.

diagnostic evaluation

(formative evaluation) a usability evaluation specifically designed to diagnose the problems with a system in order to fix them, as opposed to a measurement study that merely attempts to rate or rank a system without identifying how to make an…

diagnostic pretesting

a marketing method for determining the subjective response users will have to a given design. During a preliminary mockup stage, designs are presented to individual users and focus groups to evaluate how engaging, attractive, and persuasive different options will be.…

diary study

a study that asks people to keep a diary, or journal, of their interactions with a computer system, any significant events or problems during their use of a system, or other aspects of their working life. A diary typically asks…

discount usability

an approach to usability that seeks ways to optimize usability methods for cost-effectiveness. For instance, how can the number of users tested in user-testing be minimized while still maintaining the validity of the test? Can heuristics be found that will…

ecological validity

the extent to which the context of a user study matches the context of actual use of a system, such that it is reasonable to suppose that the results of the study are representative of actual usage and that the…

empirical methods

any of a large number of methods which are based on measurement — in user interface design, this usually means measuring the activities of people as they use computer systems. This specifically does not include theoretical methods, analytic methods, usability…

ethnography

an approach to research which involves in-depth study through observation, interviews, and artifact analysis in an attempt to gain a thorough understanding from many perspectives.

experiment

an empirical study designed to relate cause and effect by ruling out as many alternative causes as possible and by actually manipulating the cause to obtain the effect, as opposed to merely finding a correlation between the two that may…

external validity

the degree to which the results of a study can safely be generalized to apply to settings and parameters outside those of the original study, such as to other populations, times, places, similar tasks, and other measurement instruments.

extreme programming

an approach to managing programming projects to maximize the quality output of programming teams and optimize shared knowledge and training. The technique relies on pairs of programmers sharing a single computer and collaboratively solving problems. Programming tasks are kept to…

eye-tracking

a range of devices are capable of observing a person’s pupil to determine the direction of their gaze.

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face validity

the apparent appropriateness of an experimental design in resolving the question it is intended to address, at a subjective level.