The up and down movement in the data that reveals the stability or consistency in a student’s performance over time.

Verbal Behavior

Using Skinner’s Analysis of Verbal Behavior to understand how and why we use verbal behavior to communicate, and applying this analysis to teaching language skills using behavioral principles and techniques.

Vision Screening

Initial assessment of a student’s visual acuity and general observation of his or her eyes to determine the need for referral to an eye care specialist or other specialists.

Visual Acuity Test

An assessment of detailed central vision using the standard Snellen Chart and other eye charts. Infants are tested by ascertaining papillary responses to light and light fixation reflexes.

Visual Efficiency

The degree to which specific visual tasks can be performed with ease, comfort, and minimum time, contingent on personal and environmental variables; the extent to which available vision is used effectively.

Visual Supports (input/receptive)

Strategies and supports that provide a visual representation of what we want to communicate to the student, such as a daily schedule, a menu of options for free time, and one-step behavioral reminders (sit, raise hand, shh, social stories).

Visual Supports (output/expressive)

Strategies and supports that provide a visual representation of what the student wants to communicate to us, such as choice boards, an actual object, a picture of a toilet, etc.


Vocabulary development involves word knowledge, word instruction, word learning strategies and usage.

Vocal Output Communication Aid (VOCA)

A Voice Output Communication Aids (VOCA) is an electronic device that generates spoken language. Dedicated devices are intended for communication purposes only, while others are integrated into laptop computer systems. Additional features may include appointment schedules and reminders, environmental controls, switch access, and rate enhancement programs.

Vocational Assessment

A comprehensive process conducted over a period of time that serves as a basis for planning an educational program. Its purpose is to identify individual characteristics, education, and training needs.

Vocational Education

Approved educational programs offering a sequence of courses that are directly related to the preparation of individuals for paid employment with a career objective. Examples of such programs are carpentry, masonry, childcare, and cosmetology.

Voice Disorder

Problems in the pitch, quality, or resonance of the voice.

Voice Recognition

Voice recognition allows the use of a student’s voice as an input device. Voice recognition may be used to dictate text into the computer or to give commands to the computer (such as opening application programs, pulling down menus, or saving work).