Tablet PC API Glossary


A potential word match for a unit of ink. Alternates are generated by a recognizer and are based on acceptable matches of the ink against a dictionary, grammar set, or input scope.

application dictionary

A list of words, specific to an application, that are not found in either the system dictionary or user dictionary.

application gesture

A gesture that a particular application supports.

Bezier curve

A curve that is calculated mathematically to connect separate points into a smooth, free-form curve.

confidence level

A value that indicates the degree of confidence for each potential match that the recognizer returns for a particular unit of ink.

correction area

The area that appears in the writing pad when text is tapped or selected. The user can then rewrite an incorrectly recognized character or replace a word with a suggested alternative.


The point at which a stroke abruptly changes direction. The endpoints of a stroke are also considered cusps. For example, the capital letter "L" has three cusps: one in the middle and one at each end.


A set of words that a recognizer uses to determine matches and alternates.


A high-resolution hardware device that recognizes input from a pen or fingers.


See input scope.


A quick, straight stroke of a finger or pen on a screen. A flick is recognized as a gesture and interpreted as a navigation or editing command.

flick action

The action or shortcut performed in response to a flick.


A movement of a pen or fingers on a screen, which the computer interprets as a command.

grammar set

The recognition context for ink that is not in a dictionary, such as numbers, currency, or dates.

handwriting recognition

The ability of a program to interpret handwritten text and convert it into computer-readable text. Handwriting recognition programs accept input from a pen or other handwriting input device, not from a keyboard.

hot point

The distinguishing point in the geometry of a gesture. For example, the hot point of a caret (^) gesture is the apex.

human interface device (HID)

A specification that is part of the universal serial bus (USB) standard for a class of peripheral device. These devices, such as a mice, keyboards, and joysticks, enable users to input data or to interact directly with the computer.


The writing or drawing strokes that are made with a tablet pen or mouse.

ink analysis

The process of programmatically examining ink input.

ink classification

The component of ink analysis that involves dividing ink into meaningful units such as paragraphs, lines, words, and drawings.

ink collection

The process of collecting ink data from a digitizer.

ink recognition

The process of converting ink into other types of data, such as text.

ink serialized format (ISF)

A basic format used to store ink data.

ink space

The virtual coordinate space to which the coordinates of the tablet context are mapped.

ink stroke

A line of ink written or drawn on a tablet, beginning where the pen first touched the screen and ending where the pen was lifted.

Input Panel

An accessory for entering text by using a tablet pen instead of a standard keyboard. The Input Panel includes a writing pad and a character pad to convert handwriting into typed text, and an on-screen keyboard to enter individual characters.

input scope

A set of words, numbers, punctuation, and syntactical orderings that are allowed within a specific language model. Input scopes can be used by applications to restrict the language model used by the recognizer to a specific context. Previously known as fa


A point at which one stroke intersects with itself or another stroke.

language model

A set of rules for a particular language that are used as the primary context for recognizing words.


One of a set of structures that are used to pass recognition results to Tablet PC libraries. The flexibility of the lattice structures enables logical management of the large number of recognition results that can be combined into complex relationships.

layout analysis

The component of ink analysis that involves determining the position of ink on the inking surface and how the strokes relate to each other spatially and semantically. For example, layout analysis can determine that a particular unit of ink is an annotatio


A physical action, such as rotation, applied to an object.

math input control

A component of an application that is used to recognize math symbols in handwriting.

Microsoft gesture recognizer

An engine that recognizes and processes ink input as either system or application commands.

Microsoft Windows Journal Note Reader

A component that takes a stream containing a .jnt file and returns a stream containing the file's content in XML format that conforms to the Journal Note Reader schema.


A real-time, physical action applied to an object on a screen in which multiple contact points are used simultaneously.

object recognizer

An engine that recognizes general shapes according to their purpose. These objects include musical notes, geometric shapes, math equations, and flowchart elements.


The set of data sent by the tablet device at each sample point in a stroke.

recognition guide

A structure that specifies the ink boundaries to the recognizer by using ink space coordinates. In general, a recognition guide indicates what marks are drawn on the screen to help the user isolate areas for input.

recognition segment

A unit of ink interpreted by a recognizer. For western languages, this is usually a word; for East Asian languages, it is usually a character.


A software module that recognizes and processes components of one language or group of related languages, or a class of related objects such as musical notes, system gestures, and geometric shapes.

recognizer context

Application-specific information that the recognizer uses to perform ink recognition.

sketch ink object

An OLE object representing the ink that is interpreted as a drawing instead of a word.

system dictionary

A word list that contains all of the commonly written words in a language.

system gesture

A pen equivalent of a traditional mouse message, such as left-click or double-click.

Tablet PC Managed Library

A set of managed objects that extends the Microsoft .NET Framework to provide support for input and output of handwriting on Tablet PC and data interchange with other computers.

text ink object

An OLE object representing ink that is interpreted as a word.

user dictionary

A word list that contains words added to the dictionary by users.

word list

A file that contains a collection of words that make up an application dictionary.