Basic-Level Category  -  The most common level of detail in categorization. For example, "dog" is a basic-level category, while "Irish setter" (too detailed, or low-level) and "mammal" (not detailed enough, or high-level) are not.

Category  -  A category is a group of related items. The items belonging together in a category are called members of that category. "House," "dog," and "nation" are all examples of categories that each contain many different members.

Family Resemblance  -  Category members do not seem to possess all of the same traits, or even a few core traits; rather, they all resemble each other to some extent in different ways, and so are grouped together.

Feature  -  The basic parts of an object, such as orientation, shape, and color, that can be recognized with little or no high-level processing, probably by feature detectors.

Feature Detector  -  A neuron or group of neurons that fires when it receives input from the eye signaling the presence of a certain feature.

Geon  -  A limited number of shapes that, in Biederman's theory, can be used to form structural descriptions for all objects.

Mental Definition  -  A mental definition is a list of traits that a member of a certain category should possess.

Mental Imagery  -  Pictures in the mind that can be examined to perform various operations.

Mental Rotation  -  Turning a mental image of an object to achieve an imagined orientation, different from the one present in the real world.

Mental Scanning Time  -  The time it takes to move from one point on a mental image to another.

Object Recognition  -  The process of identifying an object perceived in a scene, from the signals on the retina of the eye to the placement of the object into the correct category.

Pop-Out Studies  -  Triesman's pop-out studies helped define which aspects of an item were features and which were not, based on which would cause an item to be easily found among a large group of distracters.

Prototype  -  A typical member of a particular category used to identify other objects as category members by comparison.

Structural Description  -  Structural descriptions, made up of geons, are used to identify objects.

Template  -  Templates representing each object that a person has encountered are stored in memory and used to recognize and identify objects in the future.

View-Independent  -  Shapes that are view-independent, such as geons, are equally recognizable from any angle; they never need to be mentally rotated to be compared with others.

Zooming  -  Magnifying (or shrinking) a mental image to examine a desired detail.