Chapter 2.   Issues in Multimedia Authoring

Reference: Arch, C. Luther, "Authoring Interactive Multimedia", AP Professional, 1994.
Reference: Chapters 5-8 in D.E. Wolfgram, "Creating Multimedia Presentations", QUE, 1994.

Multimedia Authoring Metaphors
Content Design
Visual Design
Technical Design

• Authoring -- the process of creating multimedia applications

• Authoring metaphor, also known as authoring paradigm, is the methodology for authoring multimedia applications.

  The following are some of the common ones:

1. Scripting Language Metaphor
   • use a special language to enable interactivities (button, mouse, etc), and to allow conditionals, jumps, loops, functions/macros
   • e.g., OpenScript in Toolbook by Asymetrix

2. Slide Show Metaphor
   • by default a linear presentation
   • e.g., PowerPoint, ImageQ

3. Hierarchical Metaphor
   • organized into a tree structure
   • seen often in menu-driven applications

4. Iconic/Flow-control Metaphor
   • graphical icons and flow chart to help authoring
   • e.g., Authorware by Macromedia

5. Card/Scripting Metaphor
   • index-card structure, good for hypertext/hypermedia
   • e.g., SuperCard, HyperCard by Apple

6. Cast/Score/Scripting Metaphor
   • with cast members, music scores, and scripting language; many synchronous horizontal "tracks" simultaneously shown in vertical columns;
   • e.g., Director by Macromedia (it uses Lingo as its scripting language)

2.2. Content Design

• What to say, what vehicle to use.

     "In multimedia, there are five ways to format and deliver your 
      message.  You can write it, illustrate it, wiggle it, hear it,
      and interact with it."                 -- D.E. Wolfgram
      

2.2.1 Scripting (writing)

Rules for good writing:

1. Understand your audience and correctly address them.

2. Keep your writing as simple as possible.
   -- e.g., write out the full message(s) first, then shorten it.

3. Make sure technologies used complement each other.

2.2.2 Graphics (illustrating)

• Make use of pictures to effectively deliver your messages.

  		               -- "A picture is worth ten-thousand words."
  
  

• Create your own (draw, (color) scanner, PhotoCD, ...), or keep "copy files" of art works.

  		               -- "Cavemen did it first."
  

• Color Themes -- be consistent with the contents
  • pastels
  • earthtones
  • metallic colors
  • primary colors
  • neon colors

2.2.3 Animation (wiggling)

Types of Animation

• Character Animation -- humanize an object

  e.g., a toothbrush, a car, a coke bottle, etc.

  Factors in choosing a character

  • Emotion -- Is it happy, sad, funny, sloppy, ...?
  • Movement -- Is it fast, slow, bumpy, ...?
  • Visual style -- Is its color/texture consistent with the rest?
  • Copyright -- "Don't use Mickey before checking with Walt."
  • Adequacy -- e.g., Does it provide various poses (can't make a broomstick sit!)

• Highlights and Sparkles

  e.g., to pop a word in/out of the screen, to sparkle a logo

  			--> to draw attention

• Moving Text

  e.g., put up one character at a time like a typewriter
  e.g., "pulsing" -- the word grows/shrinks (or changes color) a few times

  Note: Do not slowly move entire line of text, they are not readable. Instead, for example, slide the bullets in and out.

• Video -- live video or digitized video

  +: more powerful than still images
  +: often easier to obtain than graphics animation
  -: takes a lot of disk space
  -: sometimes needs special hardware

2.2.4 Audio (hearing)

Types of Audio in Multimedia Applications:

• Music -- set the mood of the presentation, enhance the emotion, illustrate points

• Sound effects -- to make specific points, e.g., squeaky doors, explosions, wind, ...

• Narration -- most direct message, often effective

2.2.5 Interactivity (interacting)

• interactive multimedia systems!

• people remember 70% of what they interact with (according to late 1980s study)

Some Common Types of Interactive Multimedia Applications:

• Menu-driven programs and presentations

• Hypermedia

• Simulations / Performance-dependent Simulations
  e.g., Games -- SimCity, Flight Simulators

• Video-conferencing (NetMeeting, etc.)

2.3. Visual Design

1. Themes and Styles

   -- A multimedia presentation should have a consistent theme/style, it should not be disjointed and cluttered with multiple themes.

   -- The choice of theme/style depends on the styles and emotions of your audience.

   Some Possible Themes:

   • Cartoon theme

     +: interesting / entertaining
     -: must be consistent with the character's personality

   • Traditional theme -- straightforward marketing pieces

     +: simple, often informative
     -: not as interesting

   • High tech theme -- contemporary computer art work (morphing, texture mapping, metal texture, explosions, ...)

     +: attractive, easy to animate

   • Technical theme -- include blueprints, 3D models of the product, ... e.g., start with a drawing, then transformed into a rendered image.

     +: shows adequate technical information
     +: gives impression of solid design and construction

2. Graphics Styles

   Reference: R. Vetter, C. Ward and S. Shapiro, "Using color and text in multimedia projections", IEEE Multimedia, Vol. 2, No. 4, pp. 46-54, 1995.

   • Some color schemes (e.g., natural and floral for outdoor scenes) and art styles (e.g., oil paints, watercolors, colored pencils, pastels) are best combined with a certain theme/style.

   Color Principles and Guidelines

   • Do not use too many colors !

   • Be consistent with the use of color

   • Use colors to separate ideas and signal changes

   Fonts

   • Size: -- e.g., Use large fonts (e.g., 18 to 36 points), no more than 6-8 lines per screen.

   • Style: -- e.g., serif vs. sans serif

3. When to Animate

   	"A leaf doesn't flutter if the wind doesn't blow."
   

   Only animate when it has a specific purpose
   • Enhance emotional impact

     e.g., dove softly flapping its wings --> peace
     e.g., air bag explosion + dummy movements --> car crash.

   • Make a point

     e.g., show insertion of a memory chip onto the motherboard (much better than a diagram)
     e.g., Microsoft Golf (instructional)

   • Improve information delivery

     e.g., "pulsing" words (in and out of screen) adds emphasis

   • Indicate passage of time

     e.g., clock/hourglass --> program still running
     e.g., animated text --> to prompt for interaction/response

   • Provide a transition to next section
     • Wipes -- e.g., L-to-R, T-D, B-U, diagonal, iris round, center to edge, etc.

     • Dissolve -- the current image distorts into an unrecognizable form before the next clear image appears, e.g., boxy dissolve, cross dissolve, etc.

     • Fade -- a metaphor for a complete change of scene

     • Cut -- immediate change to next image, e.g., for making story points using close-up

4. Pace and Running length

   A few guidelines:

   • Allow a block of text to be slowly read twice.

   • Transition time should be an indication of real-time.
     • dissolve -- time delay, scene change
     • cut -- two views of same scene at same time, or abrupt scene change

   • Running length
     • self running presentation: 2-3 minutes
     • limited interaction: 5-6 minutes
     • complete analytical, hands-on demo: < 15 minutes
     • with questions, discussions: > 30 minutes

     ** build in breaks for long presentations

5. Basic Layout

   	(a) Title
   	(b) Action area
   	(c) Narration
   	(d) Dialog
   	(e) Interactive controls
   

   • make sure that the information delivery path in the layout is smooth, not irregular/jumpy

   • use headlines/subtitles, additional shapes, buttons, fonts, backgrounds and textures to enhance the visual appearance.

2.4. Technical Design

• Technical parameters that affect the design and delivery of multimedia applications

                 * The actual number of colors displayed may be smaller, it depends
                   on the amount of video memory on the graphics card.
	
                    8-bit color -->    256 colors
                   16-bit color --> 65,536 colors
                   24-bit color --> 16.7 million colors

1. Video Mode and Computer Platform

   PC <--> Macintosh

   There are many "portable", "cross-platform" software and "run-time modules", but many of them lose quality/performance during the translation.

2. Memory and Disk Space Requirement

   Rapid progress in hardware alleviates the problem, but software is too "greedy", especially the multimedia ones.

3. Delivery
   • Live Presentation

   • Delivery by diskette

     -: Small in size, slow to install

   • Delivery by CD-ROM

     +: Larger capacity
     -: Access time of CD-ROM drives is longer than hard-disk drives

   • Electronic Delivery (Netshow/Streaming-video, etc.)

     -- depends on baud rate, network connection, and monthly bill

Further Exploration

Animation on the Web: From Server-Push to Java (Presentation slides)