Glossary » Usability Methods
a usability inspection technique that identifies the tasks that a user would perform with an application and the features of the application that would be used to perform those tasks. Each feature is then evaluated for whether it is understandable,…Read more »
a type of questionnaire designed to get a reaction to some recent experience of a person, such as a recent experience with a website or a software package.Read more »
testing a product in the actual context in which it will be used, as opposed to laboratory testing, or testing the product in its development environment. Field testing can be useful for spotting a wide range of interaction problems such…Read more »
T = k log2(D/S + 0.5), k ~ 100 msec.
T = time to move the hand to a target
D = distance between hand and target
S = size of target
Fitts’ Law is a model to…Read more »
a group of potential users or stakeholders in a product who are brought together to gather information as input to the design process. When the users are current users of a prior version of a product, the questions for them…Read more »
methods to specify user interfaces, where “formal” means that the specification notation is unambiguous, as in mathematical or computational representations. Formal methods may be used to simplify specifications, to automatically generate a user interface from a specification, or to guarantee…Read more »
the merger of multiple designs into one despite the fact that they don’t form a coherent, consistent whole. A typical situation is to present multiple design options to a client who asks for a piecemeal combination of features. While the…Read more »
a diagram used in project management, where the x axis is time and the y axis shows tasks to be performed to complete the project. Each task is displayed as a horizontal bar spanning the time period during which it…Read more »
the analysis of the difference between a technology’s capabilities and the user’s needs. This is usually informed by a user needs analysis (usually the result of user observation and requirements analysis) and is used to produce usability objectives and a…Read more »
a family of techniques for modeling and representing the knowledge necessary for a person to perform a task. GOMS is an acronym that stands for Goals, Operators, Methods, and Selection Rules, the components of which are used as the building…Read more »
an approach to analyzing interaction sequences by writing grammar-style rules to describe them and then checking those rules for consistency and simplicity. For instance, a simple set of grammar rules for text editing might include:Modify-Text –> Select-Text + Choose-Operation
…Read more »
in prototypes, the representation of text as incomprehensible words, greek or latin filler words, X’s, lines, or scribbles. Also called mumble text. The idea is to give a feel for how the page will look and be organized without needing…Read more »
a type of usability inspection; a list of rules for interface design to confirm are followed in a user interface being evaluated. These rules may include broad principles such as simplicity, may be empirically-derived results for improving speed and accuracy,…Read more »
the tendency for people to improve their performance after any change when they know their performance is being studied — a common potential confound when testing user interface changes for whether they represent an improvement or not.Read more »
a technique where user interface evaluators make estimates of how usable a system will be on a variety of quantitative criteria, as opposed to heuristic evaluation, where they merely try to identify problems.Read more »
a technique for finding usability problems with a user interface. A small number of trained evaluators (typically 3 to 5) separately inspect a user interface by applying a set of “heuristics”, broad guidelines that are generally relevant. They then combine…Read more »
(1) H = log2(n + 1).
(2) H = Σ pi log2(1/pi + 1).
H = the information-theoretic entropy of a decision.
n = the number of equally probable alternatives.
pi = the probability of alternative i…
HTA or hierarchical task decomposition, HTD; breaking down the steps of a task (process) performed by a user, viewed at different levels of detail. Each step can be decomposed into lower-level sub-steps, thus forming a hierarchy of sub-tasks. The highest…Read more »
a prototype that is quite close to the final product, with lots of detail and functionality. From a user testing point of view, a high-fidelity prototype is close enough to a final product to be able to examine usability questions…Read more »
statistics on which pages are getting visited on a website, useful for determining which pages are popular, which may be difficult to find, and which paths people are taking through the website.
The logs may contain information on what date…Read more »
describes what types of capabilities are implemented in a prototype: horizontal prototypes display a wide range of features but without fully implementing all of those features; vertical prototypes do not attempt to show all that will be in a system…Read more »
the organization of information; the field which studies how to organize information most effectively to help people find and use the information. For instance, how should websites be organized? What is the best way to design website navigation? How should…Read more »
a broad term for the design tasks of deciding how to structure, select, and present information (inclusive of information architecture, information visualization, and information retrieval).Read more »
a method of measuring optimal task times in an application by having 2 expert users compete to complete the task as fast as possible.Read more »
permission from a participant in a user study to participate and to have data collected about them, with that permission hinging on the fact that they have been fully informed of the nature and risks of the study and their…Read more »