MultimediaThe term media refers to the storage, transmission, interchange, presentation,representation and perception of different information types (data types) suchas text, graphics, voice, audio and video. The term multimedia is used to denotethe property of handling a variety of representation media in an integratedmanner. The phrase ‘representation media’ is used because it is believed themost fundamental aspect of multimedia systems is the support for differentrepresentation types. It is necessary for a multimedia system to support avariety of representation media types. It is also important that the varioussources of media types are integrated into a single system framework.
Multimediais more than multiple media. Multimedia adds interactivity to the combination oftext, graphics, images, audio and video. Creating your own media is moreinteractive than is using existing content, and collaborating with others in thecreation of media is still more interactive. Multimedia systems use a number ofdifferent media to communicate supplementary, additional or redundantinformation. Often this may take the form of using multiple sensory channels,but it may also take the form of different types of visual input – textual,graphical, iconic, animation and video. Multimedia – the combination of text,animated graphics, video, and sound–presents information in a way that is moreinteresting and easier to grasp than text alone.
It has been used for educationat all levels, job training, and games and by the entertainment industry. It isbecoming more readily available as the price of personal computers and theiraccessories declines. Multimedia as a human-computer interface was made possiblesome half-dozen years ago by the rise of affordable digital technology. Previously, multimedia effects were produced by computer-controlled analoguedevices, like videocassette recorders, projectors, and tape recorders. Digitaltechnology’s exponential decline in price and increase in capacity has enabledit to overtake analogue technology.
The Internet is the breeding ground formultimedia ideas and the delivery vehicle of multimedia objects to a hugeaudience. While we have treated various output media in isolation, it is clearthat interesting issues emerge as they are combined in what is termedmultimedia. In this sense, any computer application that employs a video disk,images from a CD-ROM, uses high quality sound, or uses high quality video imageson screen may be termed a multimedia application. Such interfaces are oftenaesthetically appealing and, where high capacity storage devices such as CD-ROMare used, can provide effective interactions for the user by acting as verylarge databases or storehouses of information with dense but easy-to-usecross-referencing and indexing.
Multimedia is all things to all people. The namecan convey a highly specific meaning or less then nothing, depending on youraudience. In fact, multimedia is a singular mix of disparate technologies withoverlapping application in pursuit of a market and an identity. We can describeit as the seamless integration of data, text, images and sound within a singledigital information environment. Multimedia finds its worth in the field ofpresenting information in a manner that is intuitive and more natural thentraditional means. A multimedia user interface must provide a wide variety ofeasily understood and usable media control tools.
In addition, information viewsneed to be integrated with structural views, since the viewing of informationwill often alternate moving through the structure by one means or another. Interactive Multimedia (IMM) is about empowering the user to explore new realmsby a variety of pathways. It is an umbrella term for a range of videodisc,compact disc and computer-based systems that allow the creation, integration andmanipulation of text, graphics, still and moving video images and sound. Thecomputer elements of an IMM system have the capacity to: ? Store, manipulateand present a range of information forms ? Allow various forms ofcomputer-based information to be accessed in linear and non-linear ways.
?Provide graphics overlay and print out screen material. ? Enable learners towork independently. ? Provide feedback to the learner Interactive multimediaprovides a powerful means of enhancing learning and information provision. Thereare however some cautions which need to be heeded if the full potential of IMMis to be realised. These can be seen listed below: ? Lack of world standards ?Technical problems ? Platforms ? Building successful teams ? Developmentalcosts Interactivity means that the user receives appropriate and expectedfeedback in response to actions taken. It is a two-way human-machinecommunication involving an end-user and a computer-based instructional system.
Users actively direct the flow and direction of the instructional or informationprogrammes which, in turn, exchange information with the viewers, processingtheir inputs in order to generate the appropriate response within the context ofthe programme. The basic elements of human interface design are now wellestablished. The user, not the computer should initiate all actions. The useraccesses and manipulates the various elements of the product by clicking onbuttons, icons or metaphors with a mouse or other pointing device. Interfacedesign should be consistent where appropriate and differentiated where needed sothe user can rely on recognition rather than recall. The user should always begiven immediate auditory or visual feedback.
User activities should be brokeninto small steps where tasks are complex. The interface design should beaesthetically pleasing, appropriate to the content and suited to the learner’sculture and prior knowledge. For designers of multimedia the main design issuesare how to integrate the media and which media to use for presenting differentkinds of information. The development of metaphorical interfaces, directmanipulation, graphical user interfaces (GUI’s) and recent advances in the fieldof virtual reality allow users to control the system by manipulating objectssuch as icons, windows, menus and scroll bars.
In well designed Interfaces,these objects are so selected and represented that users can intuitively deducetheir meaning and their function in the system from prior ‘everyday knowledge’and experience. Hypertext is a system for presenting active text. The keyfeature from the learner’s point of view is that the text has many nodes andlinks, which allow them to determine their own routes through the material. Hypertext has many applications, including use as a presentation medium forinformation management and browsing, providing access to information that thepublic needs (such as tourism information) and for various activities. Hypermedia combines aspects of hypertext and a variety of multimedia used insome combination.
The branching structure of hypertext is used with multimediain order to produce a system in which learners can determine their own pathsthrough the medium. Hypertext is the process of linking concepts within textdocuments through the use of ‘hotwords’. A hotword is an active word within adocument that the user can click on to navigate to another part of the projector to initiate some form of interaction. However navigation by hypertext can beconfusing, it can be easy for a user to become ‘lost in hyperspace’. After a fewclicks users can be so far from the original topic that they become hopelesslyconfused. Nearly all multimedia applications include text in some form.
Text andthe written language remain the most common way of communicating information inour society. The computer brings extra power to text, not only by allowing youto manipulate its size and shape but also making it an interactive medium. Theability to show moving images using digital video can greatly enhance IMMprojects. Just as video has a role in multimedia, sound also plays an importantpart in a project.
A few carefully placed sounds can greatly enhance a project,but a continuous monologue can be highly distracting. With the text-to-speechtechnology, the computer interprets text and converts it into phonetic sounds inmuch the same way as a human would. Thus, the computer can read back any textwithin any program with reasonable fidelity. This feature is very useful withinan IMM program because large amounts of text can be converted to audio withoutlarge sound files.
A particular use of this technology is to offer analternative for vision-impaired people. There are however, some disadvantages tocomputer generated speech. The speech can sound robotic compared to human speechand it lacks the variable information that can make human speakers appealing. Unlike print or graphics, animation is a dynamic medium.
We get a sense ofrelative timing, position, direction and speed of action. We need no captionsbecause the message is conveyed by the motion and the scene. Simply put,animation is the process of creating, usually graphically a series of frames andthen having them display rapidly to get a sense of movement. Video provideshigh-speed information transfer and shows temporal relationships. Video isproduced by successive capture and storage of images as they change with time. Two types of speech are available for use by multimedia developers: digitisedand synthesised.
Digitised speech provides high quality natural speech whilesynthesised speech may not sound as natural as human speech. Even with improvedtechniques for generating speech, it is not incorporated into multimediaprograms as often as it could be. This may be due to a lack of understanding ofhow high quality speech is produced. Multimedia interface designers havetypically used a navigation/map metaphor, a menu/hierarchy metaphor or a journal(sequence) metaphor. An example of the first strategy is the Virtual Museum,produced by Apple Computer.
Here the user accesses the multimedia information bynavigating through the virtual museum, moving from room to room by selectingdirections of movement. Examples of the second strategy include on-lineencyclopaedias and electronic books where a table of contents is used toorganise the material. It is helpful to view multimedia applications as aconvergence of today’s content and titles, such as movies and books of today’scomputer application programs, such as word processors and of today’s networkservices. As an example a multimedia book should have the following features. Besides text, the book has other media that the author created, including notonly text, graphics and images but also audio and video to make the book’scontent clearer or more enjoyable. Programs should be built-in to help a usernavigate through the author’s media.
Multimedia’s driving technologies, mainlydigital electronics and fiberoptic communications are making more and morefunctions sufficiently economical for consumers to use. Example applicationsinclude: Desktop Video Conferences with collaboration MultimediaStore-and-Forward mail Consumer Edutainment, Infotainmnet, Sociotainment DigitalLibraries Video on demand Hybrid Applications IMM has many applications inlibraries. IMM can bring knowledge in its entire media formats into condensed,accessible forms capable of being used for reference and educationalapplications. On the whole, within the library sector IMM is currently regardedwith some ambivalence. Many library professionals look upon it as an interestingtechnology, but one that will require significant investment and change if itspotential is to be fully realised.
Possible barriers to the effective adoptionof IMM by librarians may be cited as financial constraints and a lack ofrequisite resources resulting in a lack of opportunity to become familiar withthe new and emergent systems; ingrained traditional resistance to change; adegree of uncertainty regarding the appropriateness of the technology to variousapplications; an inability to grasp the significance of IMM and a lack ofexperience, knowledge and skills in regard to IMM among library professionals. Example applications include the Book House – a library system using hypertexttechniques to help users find books without the limitations of traditionalinformation retrieval. The user interface of the Book House is based on abuilding like a real library with the user being able to enter rooms filled withchildren’s books, adult books etc. The system supports four basic searchstrategies, using icons and pictures to enable location of the books or topicsought.
Voice response and voice recognition technologies could be used in alibrary situation, this could mean that merely speaking a unique book identifieror name could trigger the system into automatically filling in the remainder ofthe bibliographic or personal details relating to that item or person. Increasingly, multimedia systems will be developed with the aim of allowingnon-textual information to be used directly, in a demonstrational manner. Evenwhen text is present other media provide different additional information. Also,when dealing with multimedia, users are naturally disposed to interact in waysother than those developed for text. A first step to giving the user theimpression that he/she is dealing directly with non-textual material allowsdatabase search on the basis of identifying images that best suit the user’spurposes. An initial query that turns up a large number of images can be refinedby allowing the user to point a few images out of the set that contain items ofinterest.
The system can then use the text descriptions attached to the chosenimages to form a new query and offer a further set of possibly more relevantimages. My conclusion is that design could benefit tremendously from open andcollaborative multimedia research – not from relatively closed multimediapackages.