Multimedia

This document was written, and licensed for publication by MDA.

What is Multimedia?

Multimedia is one of the most 'hyped' aspects of modern computing, and has helped to generate a dramatic increase in the sales of computers to the 'small office-home office' (SOHO) market, transforming computers into a high-street commodity like video recorders or microwave ovens. A competent multimedia PC or Macintosh with pre-loaded software can be purchased for considerably less than £1,000, and is marketed as something the whole family could (and should) use

Some of the marketing can mislead people into thinking that there is something special or mysterious about multimedia, which is not the case. Strictly speaking, a television broadcast could classify as multimedia since it can contain the same range of media elements that multimedia software can - text, still images, animated images, sound and video. A more useful approach is to think of the term multimedia as an abbreviation of the term interactive multimedia, which then differentiates It from passively - received linear media such as TV programmes.

There is no official definition for multimedia, but the term is most commonly used to refer to interactive computer programs for both education and entertainment that allow non-linear navigation through the information content and contain some or all of the following media: Text, Still Images, Animated Images, Sound, Video.

Text - Can be used for titles, descriptive text, narratives, captions, hypertext (links to other topics, usually activated by clicking on a 'hot word' with the mouse), prompts and navigational aids such as button labels or instructions.
Still Images - Can be scanned from existing images or video, 2-D or 3-D diagrams, icons etc.
Animated Images - Can be either 2-D or 3-D, either simple movement of whole 'sprites ' or genuine frame by frame animation.
Sound - Usually digitally recorded ('sampled') sound, but can also encompass MIDI instrument control instructions.
Video - Just as real images can be 'scanned, ' video signals can be digitally 'grabbed' or 'captured' and recorded digitally.

What Can I Do With It?

Enhance Gallery Displays

Object information can be provided and supplemented with related information such as narratives or historical backgrounds, putting the displayed objects into context. Publicity materials such as announcements of future exhibitions or events can be displayed. Visitor guides in multiple languages can help visitors to get the most out of the museum, for example by providing tailored tours that fit in with the visitor's interests and schedule, or by helping them quickly locate the objects, facilities or information that they want.

Increase Access

More information about objects on display can be made available than with traditional labels, but in manageable 'bite-sized' chunks, because the visitor can choose which avenue of investigation to follow and therefore which information is displayed. Rich information can be provided about objects that are not on display, for example objects in store, in conservation, or on loan etc. Information about objects outside the collection can be easily and seamlessly included where appropriate.

Education

Multimedia programs can be used to enhance the educational content of gallery displays and education centres, and National Curriculum support can be provided by linking the content to the topics in different subjects and at various Key Stage levels. This support is enhanced when the program is published and can be used in schools and colleges before and after a museum visit. Multimedia information can also be educational for adults, for example in research, staff training, and in support of initiatives like National Vocational Qualifications (NVQs). This is often referred to as Computer Based Training (CBT) or Computer Based Learning (CBL), and the software is referred to as courseware.

Publishing

Multimedia programs are now a consumer commodity, the vast majority of which are published on CD-ROM (Compact Disk Read Only Memory). Although the initial costs are relatively high (creating the program, testing it and producing a master CD-ROM), once this has been achieved large volumes of disks can be pressed extremely cheaply - approximately 50p each. Other distribution media include CDi (Philips Compact Disc Interactive), LaserDisk, and traditional magnetic disk for smaller programs. The combination of the leisure/entertainment and education/training markets has given rise to hybrid terminology such as edutainment or infotainment.

How Do I Do It?

Who will produce it?

One of the first decisions that will need to be taken is the extent to which the production work will be carried out in-house, or contracted out to a multimedia production company. Whatever approach is taken, large amounts of time and usually money will need to be put in for all but the smallest projects. Most good multimedia production companies will provide as much or as little assistance as the client requires, from simply providing tools and training, all the way to producing an entire system from a few rough notes. What they generally cannot provide is the subject-specialist knowledge for the content, which is where input from the museum's staff will be of paramount importance. When contracting work to outside companies, it is very useful to get more than one proposal with storyboards and a quote, since for every reputable multimedia production company there are likely to be a number of 'multimedia cowboys.' However, there is nothing to prevent a museum from producing multimedia programs in-house, other than time and money!

Who will use it?

When planning a multimedia program, it is important to have some idea of the target audience. It is very tempting to try to produce a program that will appeal to all age groups, although it is also very difficult since the motivations, abilities and interests will vary so widely. Other factors that need to be considered about the target audience are foreign language capabilities, facilities for people with disabilities and restrictions imposed by the location of the program, such as noise pollution.

Who will pay?

The cost of developing a multimedia system is often greater than originally anticipated the curator's advice is to budget time and funds very generously, double both figures, and then allow for some extra! If money is scarce, it may be possible to obtain additional funding, for example from the European Union's 4th Framework program. There are usually quite a few strings attached, however - EU funding is usually only provides 50% of the funds and is normally only awarded to projects that involve partnerships from at least three member states.

Skills Needed

Project management - a complex series of inter-related tasks will need to be performed, some of which can occur concurrently and others that must be performed in a certain sequence.

Scripting/authoring - Multimedia programs are usually produced using authoring software, rather than traditional programming tools. Some packages use a type of 'user-friendly' programming referred to as scripting, whereas others involve no programming at all. The packages that offer scripting facilities are usually more flexible, but take longer to learn.

Content media acquisition and manipulation - The text, pictures, animations, sounds and video all have to be acquired and manipulated before they can be included in a multimedia program. For example, images may need to be scanned and edited, or sound may need to be recorded and digitised ('sampled').

User interface & navigation design - The success of a multimedia program is determined by how rewarding it is to use-if the software appears unattractive or difficult to use, it will put people off regardless of how interesting the content is. The user interface is the part of the software that the user interacts with, and often includes various on-screen buttons and controls that can be clicked on with a pointing device such as a mouse, trackball or finger. A good user interface for any type of software becomes almost transparent, so that the user is not distracted by the mechanics of controlling the software and concentrates solely on the information presented. A multimedia program also needs to look attractive and interesting enough to entice people to use and/or buy it.

A good user interface is only half of the 'usability' story though. One of the main benefits of interactive multimedia is that it can link together related topics in any way the designer sees fit. These links, often referred to as hyperlinks, determine how the user moves between the various screens of information, or pages. In order for the user to navigate confidently through the program, the layout of the various pages must be logical and obvious at all times; if they ever feel stranded or lost within the information, they will become frustrated and are unlikely to continue using the program. This phenomenon has become known as being lost in hyperspace, due to interactive multimedia's alias hypermedia.

A simple linear structure presents the pages of information in a fixed sequence, and offers the least interactivity. A branched linear structure allows the user to move up and down pathways of pages that look like an upside-down tree. A non-linear structure offers the most flexible links between pages, but increases the risk of the user getting lost within the information. One of the best ways to design the layout of the pages is to design a storyboard and page map (pen and paper is still fine for this!), that will show every screen the user encounters and the links between them. This will also help when planning the acquisition of the content and other aspects of the project.

Graphic design - As mentioned above in the section on user interface, a multimedia program must look attractive and interesting to entice people to use it-first impressions are extremely important in this respect. Graphic design is an area that is often neglected, and consequently there are now a large number of unappealing and unprofessional-looking multimedia programs commercially available.

Pedagogic factors - If the program is intended to have a serious educational role it will almost certainly be worth seeking advice from professional educationalists who specialise in courseware. Much research and investment is underway in this field; for example, the Teaching and Learning Technology Programme (TLTP) funds approximately 75 consortia of university researchers to produce educational software products.

Software needed

As with the skills needed to produce an interactive multimedia program, the software needed is likely to be diverse. Content media editing software is usually required to produce the raw materials for the authoring software to link together, although most of the larger authoring packages do come with basic content editing facilities. If the program is to be distributed, it is important that the software can produce either free-standing programs, or include a 'player' program, often referred to as a run-time version, which can be distributed royalty-free (the vast majority of packages do provide this facility).

The choice of hardware and the choice of software are closely interdependent since it is generally difficult to move multimedia programs across platforms, although Macromedia's products are available for both Mac and PC and work created on one can be used by the other to some extent. The table below names some of the more well-known multimedia authoring packages:

Product	Platform	Comments
Macromedia Director	Mac/PC	Widely used by professional multimedia companies. Extremely powerful, offering an extensive scripting language (LINGO) and animation features. Uses a film score metaphor.
Macromedia Authorware Professional	Mac/PC	Popular and easy-to-use, but not as flexible as some packages due to an extremely limited scripting capability. Uses a flow chart metaphor. Well suited to CBT.
Macromedia Action!	Mac/PC	Straightforward entry-level system.
Asymetrix Toolbook	PC only	Powerful system with extensive scripting language (OpenScript). Recently updated to provide additional functionality. Uses a book metaphor.
Apple Hypercard	Mac only	The grandparent of authoring packages, still used for Mac-only applications. Uses a stack of cards metaphor. Extensive scripting language (HyperTalk) and long history.
Apple ToolBench	Mac only	Relatively new, little information available at present.

This list does not include presentation software such as Microsoft PowerPoint, Aldus Persuasion and Lotus Freelance, or general purpose programming tools such as Microsoft Visual Basic or any of the flavours of the C programming language, although these can also be used successfully for interactive multimedia production (particularly Visual Basic). All of the PC programs mentioned here require Microsoft Windows.

Hardware needed:

As stated above, the decisions about hardware and software platforms are interdependent, and cannot be made separately. The two most commonly-used hardware platforms are the IBM compatible PC, made by hundreds of different original equipment manufacturers (OEMs), and the Apple Macintosh, made solely by Apple Computer Inc. In theory, it is possible to develop applications on one platform that can be ported to the other for final delivery, although in practice this will always present a number of additional problems.

Mac vs PC

PCs are cheaper and offer more choice in terms of both hardware and software because the platform's architecture is not licensed and they outnumber Macs in the world market by 10:1 - if developing a multimedia program to be published, the potential market is also ten times larger. On the negative side, PCs were not originally designed for multimedia and therefore some additional hardware has to be 'bolted on,' such as a sound card for playing back audio. Increasingly, however, these are fitted as an option by the OEM at relatively little extra cost.

A multimedia PC should conform to the MPC2 (Multimedia PC Marketing Council) hardware standard, which means roughly a minimum of a 486SX 25MHz processor, 4MB RAM, 160MB hard disk, SuperVGA monitor and video adapter capable of displaying 65,536 colours at a resolution of 640 pixels by 480 pixels, a double-speed CD-ROM drive (i.e. capable of a sustained data transfer rate of 300kb per second), a 16-bit soundcard, MIDI In, Out & Thru capability and Microsoft Windows 3.1 or later. For developing an application, a machine with a higher specification would be strongly recommended, for example a Pentium 90 MHz with 16MB RAM and a 2.0 GB hard disk.

Macs have always offered sound, and were traditionally the platform of choice for multimedia authoring. Whereas multimedia on PCs has only really been viable on PCs since Windows 3.0 was released in 1990, Macs have been doing it for more than ten years. Although still more expensive than PCs, they have come down in price dramatically in an attempt to remain competitive.

Recently Apple have extended the multimedia capabilities of some machines by introducing the AV range, which improve on the standard machines by adding better sound processing and video capabilities, such as on-board video capture hardware for acquiring digital video from standard analogue sources. The new PowerMacs will become the platform of choice for Macintosh authoring as the authoring software is rewritten to take advantage of the new hardware's capabilities.

Other multimedia equipment

Speakers - Plugged in to hear the output of PC soundcards, or to enhance Mac audio output.

Video Overlay Card - Used to 'overlay' a standard analogue TV/video signal on a computer monitor.

Video Capture Card - Used to record analogue TV/video signals for conversion to a digital format.

Video (De/)Compression Card - Various technologies exist to improve the quality and reduce the storage requirements of digital video on computers by providing dedicated hardware to compress and decompress the material. The technology that looks set to emerge as the victor in the digital video race is MPEG, a compression standard created by the Motion Picture Experts Group. Although software-only MPEG playback is possible, the best results will be achieved with MPEG hardware.

Videodisk player - Can play back 12' silver disks containing either: approximately 36 minutes of full motion video, or approximately 55,000 still images, both at analogue broadcast TV standard.

CD-Recordable - Special variation of CD-ROM technology that can allow once-only recording onto special gold disks using special CD writers. The resulting disk, known as WORM (Write Once Read Many) can then be used on any normal CD-ROM drive, or used as a master for a pressing in bulk. Once prohibitively expensive, these systems now start at around £3,000.

Touchscreen - Used in situations where a keyboard and/or mouse would be impractical, such as a gallery frequented by young children. To be used successfully, the user interface of the multimedia program must be designed to accommodate this type of input device. Three types of touch screen are available. The cheapest and most common type is resistive membrane, where a thin transparent film of plastic is stuck over the glass of the monitor and senses the position of a touch by the change in resistance. The second type is surface acoustic wave, which transmits beams of acoustic waves across the surface of the glass and detects when the beams are broken, much like the sensor in a car alarm. The third type is the force sensing platform, which is placed under the monitor and can calculate from the change in forces where the pressure has been applied to the screen above it-or any other object, for that matter.

Trackball - Like an upside-down mouse, a ball is rotated by hand in a fixed socket. Commonly found in laptop computers, larger trackballs exist that are suitable for putting out for public use.

References

Hoffos, Signe. Multimedia and the Interactive Display in Museums, Exhibitions and Libraries, British Library 1992.

Lees, Diane (Ed.) Museums and Interactive Multimedia (ICHIM '93), Museum Documentation Association 1993.

Lipton, Russell. Multimedia Toolkit, Random House 1992.

Sources of advice and help

British Interactive Media Association
[ http://www.bima.co.uk]

Teaching and Learning Technology Programme (TLTP)
[ http://www.ncteam.ac.uk/projects/tltp/]

MDA provides impartial resources for all aspects of collections information management. For more information please contact: Collections Link - 0845 838 4000.

Collections Link - Just Practical Advice - 0845 838 4000