A keyboard that appears on screen and accepts user input.
A person who cannot use their hands may use an on-screen keyboard combined with a head pointer.
One-Way Mirror
A one-way mirror is a piece of glass that is a mirror on
one side but can be seen through from the other side. One-way
mirrors are sometimes used in usability testing or focus
groups so that observers may watch the session without being
distracting or disruptive.
Ontology
In information technology, an ontology (pronounced ahn-TAH-luh-djee)
is the working model of entities and interactions in some
particular domain of knowledge or practices. It is a set of
concepts that are specified in some way in order to create an
agreed-upon vocabulary for exchanging information. A formal
ontology is a controlled vocabulary expressed in an ontology
representation language. This language has a grammar for using
vocabulary terms to express something meaningful within the
specified domain of interest.
Operators
In programming operators are used to combine and
manipulate expressions. They tell the computer which actions
to perform.