1. Authoring Metaphors
Introduction
Just as Desktop Publishing software expedites the production process of page design by
providing a medium where you can design the page, import components, assemble the
page, proof the publication and keep it an electronic file, so too authoring software allows
you to perform similar functions with text, audio, digitized video, live video, graphics,
animations and other resources. Multimedia authoring has four basic functions:
• Importing: Using multimedia authoring tools to import text, graphics, animations,
audio files and digitised video developed with other applications
• Creating: With a multimedia-authoring tool, you can design, edit. Paint, draw,
develop charts, capture sounds, program mathematical operations and enter text.
• Integrating: Multimedia authoring tools enable you to sequence, time, link, script,
provide feedback, keep databases of user responses and call other applications and
resources into the multimedia application.
• Delivering: multimedia authoring tools also provide for the development of self-
running application.
To help you understand the differences between the various authoring tools one must find
out on what metaphor is the authoring tool based?
The authoring process encompasses many different tasks, which usually require an
environment of tools to accomplish. All multimedia tools are based on a metaphor that
conveys how the program organizes elements, sequences events and delivers the
multimedia application. Various authoring software products take different approaches to
the organization of the environment and the way that applications are structured - this is
called the metaphor of authoring. Multimedia applications can be into four basic
categories:
The Slide Show Metaphor
The Book Metaphor/Page metaphor
The Windowing Metaphor
The Icon Metaphor
The Network Metaphor
The purpose of authoring software is to simplify the inherently complex task of creating
an interactive multimedia application. This is usually accomplished by providing an
author interface that conveys a simpler metaphor than the resulting application itself will
have. The metaphor helps the author to think about what he is doing and makes the work
seem less abstract. At the same time, an author interface helps the author by keeping
track of many details for him, making sure he does not make mistakes, and performs
other important tasks.
2. An authoring project involves many tasks:
• FILE management - Creating a file /files that that hold the authored application,
loading & saving files during authoring.
• Screen building - Creating the individual screen that makes up the presentation. This
is the most complex part and it can include selecting backgrounds, colors and styles;
entering, formatting, and positioning text; capturing or creating images and graphics;
and importing, sizing, and positioning images or graphics.
• Sequencing - Arranging the parts of the presentation into the proper order for display.
• Architecting - Defining what happens for each interactive choice by the end user and
specifying where the program instructions are kept for each part.
• User controls - The buttons, menus and other controls used by the end user must be
selected and built.
• Variables and calculations - In applications that require them, variables have to be
defined, and their contents calculated and maintained.
• Conditionals - When the application must respond to an accumulation of conditions
(not just direct user input), the logic involved must be designed.
• I/O - Applications that involve communications or hard copy output must have those
functions programmed.
• Once a presentation has been built, it should be possible to revisit any part of it and
make changes.
Testing - Running the presentations with all its elements to confirm that it runs the way
you it to.
• Delivering - The complete presentation is shown to the target audience. Either on
screen or in the form of hard copy output such as papers, 35-mm slides, or overhead
transparencies.
• Packaging - When you have to move the presentation to another platform, you have
to output it in a form that can run without the authoring environment.
• Adding dynamics - This includes selecting transitions between screens, adding
animations, capturing audio or motion video, and placing audio or motions video in
the sequence.
Thus, designing an authoring system spans a number of critical design issues like
• Hypermedia application design specifics
• User interface aspects
• Embedding/Linking streams of objects to a main document or presentation
• Storage of and access to multimedia objects.
• Playing back combines streams in a synchronized manner.
Hypermedia applications bring together a number of design issues not commonly
encountered in other types of applications. A good user interface design is crucial to the
success of a hypermedia application. The user interface aspects must really address the
other three design issues listed above.
3. The user interface presents a window to the user for controlling storage and retrieval,
inserting (embedding or linking) objects in the document and specifying the exact point
of insertion and defining index marks for combining different multimedia streams and the
rules for playing them back. The principle I/O medium of an authoring interface is the
video display screen. Because authoring involves complex operations on a number of
things at the same time, a windowed video display, as of Windows or OS/2, is usually
preferable. Recognizing that no one tool program is going to do everything in authoring,
most environments will include multiple tool programs. Usually the interface to
individual programs will be handled by the windowing operating system, and the tools
will appears icons in one or more box groups. Thus the top-level interface for a multi-
application environment is the operating system. This is where multitasking pays off -
several tools can run at the same time and you can switch between them. The tools can
also communicate data via interposes communication.
Of course, each tool has its own top-level interface, and one of the difficult aspects of
choosing an authoring environment is finding a set of tools that have similar interfaces.
The author opens the tools by double clicking on the icon in the group box. Each tool
starts up its own window on the screen. These can be minimized to icons or they can be
sized and arranged to coexist on the screen at the author’s choice. At this point all the
tools are being multitasked by the operating system, and each is using some system
RAM.
Within one tool, the top-level interface has to allow the author to move between the
different parts of the tool easily and quickly, without causing confusion and losing any of
the user’s work. It should guide the user through the process so that he performs the steps
in a logical order and doesn’t leave anything out. With today’s tools, the top-level
interface is usually accomplished by some form of menu structure, such as pull down or a
drop down menu bar, menu lists or a toolbar. These are easily understood devices, but it
may not always be easy to understand what the menu themselves mean. There can be a
problem whether the menu items are words or icons. One of the first steps in mastering a
new interface is learning the meanings of all icons and words.
Selection of an authoring tool depends on what kind of an application you are
developing. By treating each of the environments as metaphors one gets an idea of how
each one develops the application i.e., it helps the conceptualization of the application.
Below are some of the metaphors with an instance each of software that uses the
particular metaphor.
4. The Slide Show Metaphor
Here each screen of a presentation is seen as a slide object that you can separately create,
edit and arrange. This metaphor is used by PowerPoint The top level interface in
PowerPoint is a menu bar and there is a toolbar just below the menu brand a tool palette,
both of which can change depending on what you are doing. When menu items change
this way it is referred to as moding (having modes). Moding is not necessarily a good
thing - it would be better if everything in the interface always looked the same way and
always did the same things. If you choose an interface with modes, make sure it has a
clear way to tell what mode the system is in at all times so you won’t get confused.
In PowerPoint you can choose any of the four view modes (all using the slide metaphor)
for working on the presentation you are authoring. A selection of views is valuable
because it lets you emphasize different aspects of your presentation in different stages of
the authoring. View selection is made by making a selection from the view pull-down in
the menu bar; the choices are:
• Slide view:
In this view, you can see one slide at a time, displayed in fullscreen at a selectable
magnification. The magnification is chosen from the view menu or from the selector at
the right end of the toolbar. This view is most valuable for working with the details of the
slide layout.
5. • Slide sorter view -
In this view, you can see icons for all the slides in the presentation arranged in their order
of presentation. You can edit the order by dragging the slide icons around on the screen.
The magnification controls can be used to adjust the display to fit the screen or to
zooming on one area of the presentation. This view is most valuable for arranging the
order of slide presentation.
• Notes View
This is another single slide view. It shows the slide itself along with the notes that you
wish to attach to it. When making hard copy output, you can specify a format that prints
the slide with its note (or not). This view is most valuable for entering notes that you
want to attach to each slide.
• Outline view-
This view shows the text of all the slides arranged into an outline format. This view is
valuable for initial entering or editing of the text content of a presentation.
6. The screen looks so different in the four views that you will never be confused about
what mode you are in. You can begin authoring a presentation in any view of
PowerPoint, but it is probably best to first use the outline view because that will help you
organize your thoughts as well. You can view your presentation at any stage of authoring,
even just after entering an outline. Before viewing slides, apply template for the screens.
Templates make slides look uniform. You can also create your own template.
In addition to or instead of using templates you can draw each slide individually with the
draw tools built into PowerPoint. Another possibility is to use images on the slides. There
is a clip art library built into PowerPoint, contain drawings of familiar pages. These
objects can be resized, reshapes and recolored or modified for inclusion in your
presentations.
Another feature of PowerPoint that is very easy to use is specifying transitions between
slides. You pull down the transition menu and select transition effects for each slide in a
sequence.
7. Many of the representation authoring products use the slide show metaphor including
Lotus Freelance and Software Publishing’s Harvard Graphics. While this approach is
excellent for authoring linear presentations, it is not optimum when random interactivity
is needed, because you are constrained only to jumping around in a straight line of slides.
The Book Metaphor/Page metaphor
To build an application more complex than a linear presentation, with navigational and
user interactivity facilities one could select the Page metaphor. For better interactivity
you need to build a multidimensional structure. One metaphor for that is the book. One
such tool is the Asymetrix ToolBook. In this metaphor you think of an application as a
book containing any number of pages or discreet units of information/interaction linked
together to form a sort of a book. Each page is a screen shown in its own window, which
can contain any number of multimedia objects and any amount of interactivity. A page is
richer architecture than a slide because you can arrange interactivity within the page.
Toolbook displays only one page at a time, in a single window, and you can navigate the
application by displaying different pages.
A page in a book can also start other books, so an even more complex hierarchy can be
built. When you start another book, you are actually beginning another instance of
Toolbook, so each book can exist in a different window with its own characteristics.
Multiple instances are one of the advantages of a multitasking environment and it is not
wasteful only one copy of the tool’s executable file is required.
All window and dialog generation in ToolBook can be done graphically with the mouse,
including drawing objects, choosing colors and placing text objects. Standard objects like
pushbuttons and check boxes etc. have a default behavior built in, which provides the
standard highlighting behavior of Windows. However to assign custom behavior to a
control or other object you write a handler in the OpenScript language. Handlers are code
modules that define the response to any event that occurs in the application. Events result
from user actions, or they can be created by the application itself. Each object has an
associated script, which contains any handlers that object requires. Although OpenScript
is an easy to read language, it is a full-featured programming environment, and elaborate
ToolBook applications will take a lot of programming. These way more dynamic
applications can be built.
TheToolBbook authoring environment has a main window with a menu bar that provides
access to all functions. There also is a tool palette, shown at the left, and a number of
other palettes that can be optionally displayed all the time. The command window allows
OpenScript commands to be typed in and immediately executed. The authoring
environment also includes some aids for writing scripts, such as a recorder that can create
a script from actions you do with the mouse.
8. Multimedia Toolbook supports audio, video and animation by using the MCI and DDE
interfaces of Windows. These take some significant script writing. Although ToolBook
can be used by a nonprogrammer, accessing the real power of it requires programming
skill.
Recently the Page Metaphor has become very popular because it is the primary one
employed on the Web. If you anticipate eventually moving your CBT projects to the
Internet, using an authoring tool with a page metaphor will make your job easier in the
future.
9. The Windowing Metaphor
Several systems offer a programming approach to authoring. Programming refers to a
series of explicit instructions that the computer performs. In general, programming is
more difficult than visual authoring with pages, flowcharts and icons. The main
Advantage: programming lets you control the detailed aspects of the operation of a
project. The main disadvantage: programming is more time consuming.
Applications in Windows and OS/2 use the windowing metaphor for their user interface.
This is also a valid approach for muiltimedia authoring. A window is an on-screen object
that the user interacts with. Objects and controls in the window are all considered to be
children of the window and receive their control via the window. This concept provides a
hierarchy for multimedia objects by requiring them to be grouped into windows and
requiring the windows themselves to be arranged into a hierarchy or parent-child
relationship.
It is important for Windows or OS/2 authoring system to be able to author windows in
any configuration desired and as many times as desired. ToolBook can author only a
single window per instance of the program. But the metaphor of ToolBook is really the
book-and-page concept, and the window required for each book is a secondary concept.
On the other hand, Microsoft’s Visual Basic uses the window as its metaphor and its
architecture - all the features of authoring are tied to one or more windows. It has many
similarities to ToolBook but there is no book-and-page architecture built in. So you are
not limited to a book and page approach as in ToolBook but VB will not give you a
predetermined structure to depend on leaving you to build something similar instead.
Visual Basic is a language-based assembly package that offers graphical authoring of
windows and their contents (objects) and then provides language based authoring of the
behavior of the objects. (Like ToolBook). It is easy to create the windows - as many as
you need for an interface and if you are a programmer, it is easy to attach code blocks to
any kind of event for an object that requires custom behavior. Major interactive
applications can be built with this environment. This environment provides a good set of
debugging tools and when your application is complete and correct, it can be compiled
into a standard Windows executable format so it will be run by itself under Windows.
The author interface of VB is shown above.
The main menu of Visual Basic is at the top along with a window Profiles) that is
currently being authored. (Visual Basic calls each window a form). Other windows of the
environment include a tool palette at the left, an index of all the files in the current
project. A color palette at the bottom, a window (Properties) listing the properties of the
selected object and a code window for some code that is attached to the Profiles form.
Those code runs every time the Profiles window is started up.
10. The environment provides tools for creating windows, adding many types of objects to
windows, specifying attributes for each type of object, drawing and adding text to
windows, and adding text to windows and attaching code to all kinds of events that could
happen with a window or object. The system takes care of almost all of the structuring of
your application’s code - you only have to write the individual code modules.
Some authoring tools offer only icons; others offer only a programming language. A few
systems let you use either approach: you might see it described as “visual authoring plus
available programming”. In general, an authoring system with both approaches gives you
the flexibility to create almost anything, and helps you maximise your productivity.
A final note: Programming comes in two flavours ; propriety and standard. A propriety
language is unique to that system; a standard language is version of a popular one, such
as Basic or C. An authoring system vendor can tune a propriety language to match user
needs. However, fewer people will know that language and therefore labor costs will be
higher. It’s probably better to go with an authoring system with a standard programming
language where books and help sources are available.
11. Timeline / Flowchart Metaphor
Many authoring systems employ a flowchart/timeline metaphor: they let you assemble
materials into a sequence, as if you were creating a sort of “movie”. This metaphor can be
useful for a project that has definite starting point, path, ending point, such as a
presentation, animation or game. Tools using this paradigm are Action, Macromedia
Director, Stanford University’s MAEstro.
This is also called the Cast/Score/Scripting paradigm where the synchronous elements are
shown in various horizontal tracks, which are simultaneously shown via the vertical
columns. Some applications, or parts of applications, lend themselves to timeline
authoring. With this metaphor you work with a time scale diagram and you place objects
and events on the time scale in correct relationship to each other. This is especially
valuable when you are dealing with a lot of animation or other dynamic activity.
Macromedia Action! and Director are good examples of presentation assembly program
that contain the timeline approach.
Action! builds a presentation as a sequence of scenes. The scenes are treated the same as
slides are in slide oriented presentation authoring - they can be individually treated and
arranged in a slide sorter. The difference with a scene is that it is in animation in which
you can control separately the behavior of every element. Each scene has a timeline that
details exactly when each part of the scene takes place and for how longs. By double
clicking on an object in the timeline the Edit Object dialog comes up for that object. .
With the dialog all the properties of the object and its behavior can be entered or edited.
The control panel window at the lower right of the screen allows the presentation to be
previewed at any time. Objects are selected from a tool palette.
Action! Provides interactivity by allowing any object in a scene to become a button.
When the user clicks a button, control can be sent to any other scene. Thus you can build
an application with a number of scenes, and you user could random access to any scene.
It is generally accepted that the Flowchart/timeline metaphor is less than ideal for CBT
projects. CBT authors indicate that a flowchart is the least desirable feature in a CBT
12. authoring system. CBT project often need to branch in many different directions based on
user input, scores, etc. Trying to create and maintain such complex branching is very
tedious, if not impossible with a timeline metaphor.
The Network Metaphor The ultimate interactive application would allow the user to
move from any object in the application space to any other object without restriction.
This is full random access, and maybe you wouldn’t want all of it very often, but it is the
most unrestricted concept of interactivity. Many assembly tools use hierarchical models
of some sort, but these cause restrictions in that you must move between objects via the
paths in the hierarchy. For some kinds of applications you would like to have a more free
environment that has no restrictions on where you can go. An approach to that is the
network metaphor as employed in MEDIAscript
The network metaphor can be built with any programming language, but it requires that
the author be a programmer, and it provides no help to him in maintaining the
application. An assembly program should provide that kind of help to an author.
An authoring package that implements the network metaphor is MEDIAscipt from
Network Technology Corporation. In MEDIASscript an author builds a group of objects
or functions in the form of scripts, which can be interconnected in a completely general
fashion. A script is an executable object: it can be simple or complex. Scripts are built
from a set of multimedia objects, 14 types in all that support all of the functions of a full-
features programming language. However the authoring interface is graphical: objects are
selected from a palette and placed into scripts, and the characteristics and behavior of
each object are authored via dialog boxes. There is a script window at the left of the
screen and the palette of objects is shown at the top of the screen. There are only 14
object types, but that small number encompasses all the capabilities of a full featured
authoring language that lies behind MEDIAscript’s graphical authoring interface. Scripts
in MEDIAscript are organised by using its Organizer tool. A script always runs from the
beginning, but it can have any number of exit points, called links. Each link is given a
name during the authoring of a script, and those names appear in the Organizer window
as an item next to the item for its parent script. In the Organizer, the author connects each
exit point to the start of another script. There are no restrictions on this process, so a
network of any degree of complexity can be built. Each link and its connection in the
Organizer window have arrows that allow the author to traverse the network either
forward or backward to see the application structure.
14. The Icon Metaphor
An authoring metaphor that is particularly suited to authoring by non-programmers is the
Icon metaphor. Most authoring tools use icons in one form or another. An icon is a
pictorial representation of an object, container or process. An authoring system may
contain icons for text, buttons, pictures etc.; often clicking on an icon lets you then
modify the item it represents. This metaphor is the basis of Aimtech’s IconAuthor as well
as Macromedia’s Authorware product. Here the application structure is built by
dragging icons from an icon palette into the application workspace and connecting them
to create the logic of the application. This is usually done as a flowchart. Then each icon
is “opened” to reveal a dialog box that allows the properties and the content of that object
to be defined. No scripting is required, and there is no language.
There are about 50 types of icons in IconAuthor, which provide support for all computer
functions and all multimedia functions. Audio, video and animation are supported via
MCI. DDE is also supported. Most of the flexibility of a language is provided in
IconAuthor, without requiring any programming. However developing sophisticated
applications is still a difficult and complex task, but the author can concentrate on the
application logic and content rather than on the details of programming and language
syntax. But concentrating on logic still embodies some of the structural concepts of
programming - an author planning to do complex applications will need training in the
concepts, loops, data structures, nesting etc.
16. There are both good and bad aspects to icons for CBT projects. Icons help you visualize
the content of a project, and they can be easy to manipulate for simple projects. However
if the icons grow too numerous, they become confusing. Icons are not substitutes for
programming. There is no an authoring system can have enough icons to support all the
things needed by CBT developers. Attempts to do so typically result in projects with a
mind-numbing array of indistinguishable icons. That’s where available programming
comes in.
Each metaphor has advantages and disadvantages; the choice between them depends on
the kinds of work you will be doing and on your personal preferences. One can also ask
oneself the following classes:
• What is my expertise in programming?
• What is the expertise within my team?
• What is the purpose of the proposed application?
• How fast does my client want this project done?
• What is the budget?
• How fancy does the application need to be?
Suggested software for different uses:
Proposed Use Suggested Software
Business Astound
Macromedia Action
Macromedia Authorware
Education Macromedia Director 5.0
Macromedia Authorware
Asymetrix ToolBook
HyperCard
Games Macromedia Director 5.0
In general Macromedia Authorware and Asymetrix ToolBook are good in terms of
overall interactivity and Macromedia Director is the best choice for developing
multimedia interactive applications loaded with animations and rich sound.
