|New Training Technologies (ILO - UNEVOC, 1995, 95 p.)|
23 This glossary is mainly an extract from that published in "An Introduction to IBM Multimedia Solutions" - November 1991; some definitions have also been taken from "Le nouveau dictionnaire Marabout de la micro-informatique" - Marabout Informatique - 1990.
ADPCM (Adaptive Differential Pulse Code Modulation):
a standard encoding format for storing audio information in a digital compressed format.
refers to any operation in which data are represented by a continuous physical flow; as opposed to digital.
ANSI (American National Standards Institute):
responsible for the setting of computer standards.
in computing, refers to the philosophy of computer hardware design; open architecture indicates systems which allow for the addition of peripherals and internal enhancement cards from third-party manufacturers; closed architecture systems are advertised as "all-in-one-box" solutions, discouraging users from adding memory, etc.
ASCII (American Standard Code for Information Interchange):
the standardised 8-bit data character code used internationally to code alphabetic, numerical and other symbols into the binary values.
specialized high-level computer language which permits non-programmers to develop courseware; program logic and content are combined; offers fewer capabilities or options than an authoring system.
specialized computer software which helps users to design interactive courseware without computer programming; instructional logic and content are separate; allows greater flexibility than an authoring language.
the range of signal frequencies that a piece of audio or video equipment can encode and decode; video uses higher frequency than audio, thus requiring a wider bandwidth.
consumer videotape format developed by SONY (1/2" tape).
a 1/2" video recording format developed by SONY that offers near 1" quality tape on a portable system.
graphic image made of a certain number of points per inch; bitmap files are rather large but may be condensed.
in the USA a standard of 525 lines of video picture information at a rate of 60 Hz; in Europe, 625 lines at a rate of 50 Hz.
a circuit or group of circuits which provides an electronic pathway between two or more CPUs or l/O devices; popular computing buses include IBM PC bus, ISA bus, EISA, MACINTOSH Nubus.
temporary storage for data requiring quick access.
a lightweight hand-held videotape camera/recorder.
CAV (Constant Angular Velocity):
a mode of videodisk playback in which a disk rotates at a constant speed, regardless of the position of the reading head; each frame is separately addressable; CAV disks rotate at 1800 revolutions per minute (NTSC) or 1500 rpm (PAL), one revolution per frame.
CCITT (Consultative Committee for Telephony and Telegraphy):
an international standards organisation dedicated to creating communications protocols.
CD-A (Compact Disk Audio):
optical disk (12 cm) that contains musical information encoded digitally; 74 minutes of high-quality digital sound; standard developed by PHILIPS and SONY, known as the "Red Book".
CD-I (Compact Disk Interactive):
a digital compact disk recording interactive applications made of text, audio, images, animation and compressed video; a standard developed by PHILIPS and SONY, known as the "Green Book".
CD-ROM (Compact Disk Read-Only Memory):
an optical memory storage (12 cm) in the CLV format; can hold about 600 Mb: a standard developed by PHILIPS and SONY is known as the "Yellow Book".
CD-ROM XA (Compact Disk Read-Only Memory Extended Architecture):
an extension of the CD-ROM, a step between CD-ROM and CD-I, promoted by PHILIPS and MICROSOFT; the extensions add ADPCM audio and permit the interlacing of sound and video data for animation and sound synchronisation.
CISC (Complex Instruction Set Computer):
most computers on the market use this system, as opposed to those which use the RISC (Reduced Instruction Set Computer).
CLV (Constant Linear Velocity):
an alternative format for laser videodisks which allows twice as much playtime per side, but does not offer many of the user-controlled capabilities; it can be read in linear play only; the revolution speed varies with the location of the pickup to ensure a constant data rate; the speed for a NTSC disk varies from 1,800 rpm at the inner track to 600 rpm at the outer edge.
used to describe different hardware devices that can use software or play programs without modification.
the separation of chrominance (colour) and luminance parts of the video signal; these two signals are recorded separately which helps to maintain better picture quality over more generations.
a colour video signal that contains all of the colour information in one signal; the complete visual wave form of the colour video signal composed of chromatic and luminance picture information.
to reduce certain parameters of a signal while preserving the basic information content; compressing usually reduces a parameter such as amplitude or duration of the signal to improve overall transmission efficiency.
a video image or segment that has been digitally processed using a variety of computer algorithms and other techniques to reduce the amount of data required to accurately represent the content and thus the space required to store it.
the translation of data to a more compact form for storage or transmission.
CBT (Computer-Based Training):
the use of computer to deliver instruction or training.
visual images generated by a computer; graphics standards include CGA, MCGA, EGA, HERCULES, VGA, SVGA, XGA, etc.
instruction software including ail disks, tapes, books, charts and computer programs necessary to deliver a complete instructional module or course.
software that tells the computer how to talk to a peripheral device, such as a videodisk or a printer.
DDE (Dynamic Data Exchange):
a form of interprocess communication supported in Microsoft Windows and IBM OS/2; when two or more programs that support DDE are running simultaneously, they can exchange information and commands.
a method of signal representation by a set of discrete numerical values, as opposed to a continuously fluctuating current or voltage (i.e. analogue).
audio tones represented by machine-readable binary numbers rather than analogue recording techniques; analogue audio is converted to digital using sampling techniques whereby a "snap shot" is taken of the audio signal, its amplitude is measured and described numerically, and the resulting number is stored; more frequent sampling results in a more accurate digital representation of the signal.
a video signal represented by computer-readable binary numbers that describe a finite set of colours and luminance levels.
to register a visual image or real object in a format that can be processed by a computer; to convert analogue data to digital data.
an efficient colour coding scheme for natural pictures used in CD-I; the human eye is less sensitive to colour variations than to intensity variations; so, DYUV encodes luminance (Y) information at full bandwidth and chrominance (UV) information at half bandwidth or less, storing only the differences (deltas) between each value and the one following it.
EISA (Extended Industry Standard Architecture):
internal 32-bit bus, an enhancement of 8/16 bit ISA (IBM PC/AT) architecture, developed by several computer manufacturers in 1988 as a response to IBM's MCA (Micro Channel Architecture) bus; offers full compatibility with ISA bus and boards.
Fax (or facsimile):
to electronically scan and copy a replica image of a document for transmission via telephone lines or other means.
the technology in which audio/visual signal/information is transmitted through a glass fibre strand capable of transmitting light.
a single, complete picture in a video or film recording; a video frame consists of two interlaced fields of either 525 lines (NTSC) or 625 lines (PAL/SECAM) running at 30 frames per second (NTSC) or 25 frames per second (PAL/SECAM): a film runs at 24 frames per second.
a device that stores one complete video frame.
the speed at which video frames are scanned or displayed; 30 frames per second for NTSC; 25 for PAUSECAM.
a single frame from a segment of motion video held motionless on the screen; unlike a still frame, a freezeframe is not a picture intended to appear motionless, but is one frame taken from a longer motion sequence.
educational courses that are not specific to one organization and thus appeal to a broader market; as opposed to custom courseware, which primarily meets the needs of one specific client or audience.
prefix meaning "one billion"; as in Gb (one million bytes).
GUI (Graphics User Interface):
a visual metaphor that uses icons representing actual desktop objects that the user can access and manipulate with a pointing device.
Graphic file formats:
- EPS (Encapsulated Postscript):
designed by ALDUS to provide a way to display Postscript images; EPS stores a Postscript description along with a bit-mapped equivalent of the image that can be displayed on the screen;
a MACINTOSH specific multimedia format for exchanging animation sequences; assembles several PICT files (frames) and combines them into one file;
- PICT (Picture Format):
developed by APPLE in 1984 as the standard format for storing and exchanging black-and-white graphics files; PICT2 (1987) supports 8-bit colour and grey scale;
- RIFF (Raster Image File Format):
an extension of TIFF devised by graphics developer LETRASET;
- TIFF (Tag Image File Format):
a format for storing and exchanging scanned images (developed in 1986 by ALDUS with MICROSOFT and others) which is compatible with several personal computing platforms, including IBM and MACINTOSH.
the standard unit of measuring frequency; one Hz is equal to one cycle (or vibration) per second.
the high-quality extension of the Video8 (or 8 mm) format which features higher luminance resolution.
an extension of hypertext that incorporates a variety of other media in addition to simple text.
the concept of non-sequential writing which allows writers to link information together through a variety of paths or connections; hypertext allows users to seek greater depths of information by moving between related documents along thematic lines or accessing definitions and bibliographic references without losing the context of the original inquiry.
the methodology and approach used to deliver information in a manner that achieves learning.
involving the active participation of the user in directing the flow of the computer or video program; a system which exchanges information with the viewer, processing the viewer's input in order to generate the appropriate response within the context of the program; as opposed to linear.
a method of storing information sequences in an alternating series of frames.
ISA (Industry Standard Architecture):
standard name for IBM PC/AT computer bus architecture.
ISDN (Integrated Services Digital Network):
an international digital telecommunications standard developed to enable transmission of simultaneous high band with data, video, and voice signals (all digital).
ISO (International Standards Organization).
JPEG (Joint Photographic Experts Group):
a working committee of the ISO defining a proposed universal standard for the digital compression and decompression of still images for use in computer systems.
a small keyboard or section of a keyboard containing a smaller number of keys.
Kilobyte (K or Kb):
a term indicating 1024 bytes of data storage capacity.
LAN (Local Area Network):
a system which connects two or more microcomputers to allow shared resources and communication.
LASER (Light Amplification by Stimulated Emission of Radiation):
an amplifier and generator of coherent energy in the optical, or light region of the spectrum.
common name for reflective optical videodisk; a laser is used to read the micropits on the disk which contain the picture and sound information.
a motion sequence designed to be played from beginning to end without stops or branching, like a film; as opposed to interactive.
brightness; one of the three image characteristics coded in composite television, represented by the letter Y; may be measured in lux or foot-candles.
any medium (generally tape or disk) upon which information is encoded as variations in magnetic polarity.
an information storage medium that is magnetically sensitive only at high temperatures, while stable at normal temperatures; a laser is used to heat a small spot on the medium, allowing a normal magnet to change its polarity; the ability to tightly focus the laser greatly increases the data density over standard magnetic media.
prefix meaning "one million"; as a Mb (one million bytes) or a MHz (one million hertz).
MCA (Micro Channel Architecture):
revised bus of PC architecture introduced by IBM in some PS/2s; incompatible with original PC/AT (ISA) architecture.
MIDI (Musical Instrument Digital Interface):
an industry standard connection for computer control of musical instruments and devices.
contraction of MOdulator/DEmodulator; digital device that converts data from a computer into signals that can be transmitted over ordinary telephone lines, and vice-versa.
a process whereby information is converted to some code, and the code is made part of a transmitted signal; the opposite process is demodulation.
MPEG (Motion Picture Experts Group):
a working committee of the ISO defining standards for the digital compression and decompression of motion video/audio for use in computer systems.
refers to the delivery of information, usually via personal computers, that combines different formats (text, graphics, audio, still images, animation, motion video) and/or storage media (magnetic disk, optical disk, video/audio tape, RAM).
one-billionth of a second.
NTSC (National Television Systems Committee) of the EIA (Electronics Industries Association):
a colour television format having 525 scan lines; a field frequency of 60 Hz; a broadcast bandwidth of 4 MHz; a frame frequency of 1/30 of a second; a colour sub frequency of 3.58 MHz.
architecture used in MACINTOSH II series of APPLE computers.
OLE (Object Linking and Embedding):
open specification that will enable developers to more easily integrate information created by different applications by making simple extensions to existing graphic applications which run under WINDOWS, OS/2 PM and APPLE MACINTOSH System 7.0.
OOP (Object-Oriented Programming):
a programming methodology in which every element in a program is self-contained.
a generic term for technology that deals with information storage devices that use light (usually laser-based) to record, read or decode data.
the facility to superimpose computer generated text and/or graphics onto motion or still video.
the transfer of data by means of addressed packets (or blocks) of information, whereby a channel is occupied only for the duration of transmission of the packet; in contrast with circuit switching, the data network determines the routing during (rather than prior to) the transfer of a packet.
PAL (Phase Alternation Line):
the European standard colour system, except for France, Russia and Eastern European countries.
also called Credit Card Adapter; a credit card-like PC adapter for portable PCs; exists in different thicknesses (3.3, 5.0, 10.5 mm), typically used for memory or other input/output functions (e.g. modems, harddisk); any PC Card can be installed and functions in any system supporting the PCMCIA specified interface.
PCM (Pulse Code Modulation):
a standard means of encoding audio information in a digital format by sampling the amplitude of the audio wave-form at regular intervals and representing that sample as a digital numeric value.
PCMCIA (Personal Computer Memory Card International Association):
a non-profit association of more than 300 members which is setting standards for PC Cards.
the microscopic physical indentation or hole found in the information layer of a videodisk.
an abbreviation of picture element, the minimum raster display element represented as a point with a specified colour or intensity level; one way of measuring picture resolution is by the number of pixels used to create images.
Pulse code or pulse:
a signal which, when recorded on every frame of a videotape, facilitates editing and access by making individual frames easier to identify.
a step in the process of converting an analogue signal into a digital signal; measures a sample to determine a representative numerical value that is then encoded; the three steps of converting analogue to digital are: sampling, quantising and encoding.
the area illuminated by a scanning beam of a TV system; a raster display device stores and displays data as horizontal rows of uniform grid or pictures and sound from a videotape to a monitor.
number of pixels per unit of area; a display with a finer grid contains more pixels and thus has a higher resolution, capable of reproducing more detail in an image.
a type of computer colour display output signal comprised of separately controllable red, green and blue signals, as opposed to composite video in which signals are combined prior to output; RGB monitors typically offer higher resolution than composite.
a standard serial interface between a computer and its peripherals.
RTOS (Real-Time Operating System):
CD-I operating system, developed by MICROWARE.
the process of taking measurable slices of an analogue signal at periodic intervals; a step in converting an analogue signal into a digital signal.
rate at which slices are taken from analogue signals when converting to digital; frequency at which points are recorded in digitizing an image; sampling errors can cause abasing effects.
strong, bright colours (reds and oranges) which do not reproduce well on video, but tend to saturate the screen with colour or bleed around the edges producing an unclear image.
SCSI (Small Computer Standard Interface):
a device-independent interface used for a wide variety of computer peripherals.
SECAM (SEquentiel Couleur A Memoire = sequential colour with memory):
the French colour TV system also adopted in Russia, Eastern Europe and ex-French Africa; the basis of operation is the sequential recording of primary colours in alternate lines.
an outer layer of a program that provides the user interface or the user's way of commanding the computer.
a device that produces human speech sounds from input in another form.
a single film or video frame presented as a single, static image; refers to information recorded on a frame or track of a videodisk that is intended to be retrieved and displayed as a single, motionless image.
a higher-quality extension of the VHS home videotape format, featuring higher luminance and the ability to produce better copies.
type of video signal used in the Hi8 and S-VHS videotape formats; it transmits luminance and colour portions separately, using multiple wires, thus avoiding the NTSC encoding process and its inevitable loss of picture quality; (see also: Y/C video).
the precise coincidence of two pulses or signals, as in the sync pulses of a videotape recorder locked in with the sync pulses of a camera.
a general term for a meeting not held in person; usually refers to a multi-party telephone call set up by the phone company or private source, which enables more than two callers to participate in a conversation; the growing use of video allows participants at remote locations to see, hear and participate in proceedings, or share visual data (see also: video conference).
computer information inserted into the normal broadcast signal; a one-way information system.
VCR (Videocassette Recorder):
generic term for home videotape device.
line drawing; a vector display device stores and displays data as line segments identified by the x/y co-ordinates of their end points.
VHS (Video Home System):
consumer videotape format developed by Matsushita and JVC.
a teleconference (see also teleconference) with bidirectional images transmission, using high-definition TV cameras; it allows participants to see each other as well as any object which is in the room; terrestrial and/or satellite communications can be used.
Video 8 or 8 mm video:
video format based on the 8 mm videotapes popularised camcorders.
generally classified by the width of the magnetic tape:
- 1" used for professional or "broadcast" quality video recording and editing;
- 3/4" U-MATIC (SONY) used by most industrial video;
- 1/2" primarily used consumer format (VHS and BETA) and their high-quality formats (S-VHS, SUPER BETA);
- 8 mm popularly used in hand-held camcorders; provides high quality recording in tiny tape format.
a collective name for systems which use the domestic TV receiver to display data from a central computer transmitted to the set via coaxial cable or telephone link; a special set of fairly low-resolution text and graphic characters that can be displayed via specific decoders.
a computer-generated "reality" into which users may enter by virtue of bodily peripherals such as data gloves and head-mounted computer graphic displays.
a computer input technology in which a human utterance is recognised within the computer terminal and then converted into machine-usable binary code.
WAN (Wide Area Network):
the integration of geographically distant or technology incompatible LANs.
WORM (Write Once/Read Many):
a type of permanent optical storage that allows the user to record original information on a blank disk, but does not allow erasure or change of that information once it is recorded.