APPENDIX B.6 : MICROCOSM
Introduction
Microcosm is a hypermedia system which allows users to browse and query large
multimedia collections. However, Microcosm is fundamentally different to most
hypermedia systems because of its ability to integrate information produced
using a variety of third-party applications (Figure 3). Microcosm can be seen
as an 'umbrella' environment allowing the user to make links from documents in
one application to documents in another. Microcosm has been used within the
educational field, for large archives, an Urban Information System, for
computer aided engineering and for delivering multimedia materials in a range
of other applications.
Wherever people have seen the system they have been excited by the
possibilities that it offers. Academic courseware authors have been quick to
see the advantages over current hypermedia and presentation packages. The
following paragraphs describe just some of the aspects that contribute to
making Microcosm such a novel system.
Microcosm Figure 1: The Microcosm Model
The Microcosm Model
Microcosm consists of a number of autonomous processes which communicate with
each other by a message-passing system (Figure 1). No information about links
is held in the document data files in the form of mark-up. Instead, all data
files remain in the native format of the application that created them. All
link information is held in link databases (linkbases), that hold details of
the source anchor (if there is one), the destination anchor and any other
attributes such as the link description. This model has the advantage that it
is possible to have different sets of links for the same data, and also it is
possible to make link anchors in documents that are held on read only media
such as CD-ROM and videodisc.
Microcosm allows a number of different actions to be taken on any selected item
of interest, so use of the system involves more than simply clicking on buttons
to follow links. In Microcosm the user selects the item of interest (e.g. a
piece of text) and then chooses an action to take. A button in Microcosm is
simply a binding of a specific selection and a particular action.
An important feature of Microcosm is the ability to generalise source anchors.
A spectrum of link possibilities exists, from explicitly defined anchors to
dynamically generated anchors (Figure 2.):
Specific Links
The user is able to follow the link only after selecting the anchor at a
specific location in the current document. Specific links may be made into
buttons.
Local Links
The user is able to follow the link after selecting the given anchor at
any point in the current document.
Generic Links
The user is able to follow the link after selecting the given anchor at
any point in any document. Generic links are of considerable benefit to the
author in that a new document may be created and immediately have access to all
the generic links that have previously been defined.
Dynamic Links (e.g. Computed Links)
Not all links need to be created by an author. For example,
relationships between pieces of information can be computed, based on
statistical analysis of the content (e.g. Computed Links), or related
information can be retrieved based on attribute coding of documents. The basic Microcosm processes are viewers and filters.
Microcosm Figure 2: Following Links
Viewers
Viewers are programs which allow the user to view a document in its
native format. The table below shows viewers currently included, and 3rd party
applications with Microcosm enabled for Microcosm linking:
Text Word for Windows
Word Perfect for Windows Ami Pro
Bitmaps AutoCad
Animations Video
ToolBook Authorware Professional
Superbase 4 Mimics (guided tours)
Audio
Table 1: Viewers Currently in Use with Microcosm
The task of the viewer is to allow the user to peruse the document, to make
selections and to choose actions. Typical actions are follow link, start link
and end link (where links may be to processes as well as to documents). The
actions themselves are not effected by the viewer. The viewer is responsible
for binding the information into a message, which is sent on to the filter
chain where it will look for one or more processes that can satisfy this
request.
An application's ability to communicate with Microcosm will fall into one of
the following categories:
Fully aware
A fully aware viewer is one which has been written explicitly to
communicate with Microcosm. A bi-directional message channel exists between the
viewer and Microcosm, allowing the viewer to issue requests, for example to the
linkbases for buttons. Such a viewer is able to receive replies also, such as
in response to a button request telling it which areas of the text to
highlight to indicate the presence of any buttons retrieved.
Partially aware
These are usually applications that can be tailored by the user, e.g.
Word for Windows. Microcosm is able to control which document the application
should open. In addition, the user is able to follow or create generic links
from within them, but the viewer is not capable of full communication with
Microcosm as it cannot receive messages.
Unaware
These are applications that have no direct communication with Microcosm.
However, it is possible to launch the viewer with the correct document and
mechanisms are available to enable some communication with Microcosm (e.g. via
the clipboard).
Microcosm Figure 3: Microcosm as an environment for integrating applications and tools
The ability to make third-party applications 'Microcosm aware' or to use the
clipboard to communicate means that Microcosm is more than just another
hypermedia system. Instead, it can be seen as a means of integrating the
applications which constitute the existing working environment, rather than
just adding to the clutter of the desktop.
Filters
Filters are processes which are responsible for receiving messages, taking any
appropriate actions, and then handing the message on to the next filter in the
chain. The actions that filters take are such as changing a message, or adding
or removing messages.
The filters currently provided with Microcosm are:
- Linkbases
- Show Links
- Compute Links
- Navigational aids
- Link construction filter
The order that the filters appear in the chain is under user control. Filters
may be installed and removed in order to configure the system according to the
user's preference.
Linkbases
Linkbases hold all the information referring to links. More than one
linkbase may be installed at a time, making it possible to provide different
views of the information by installing two separate link sets. A 'public'
linkbase may contain all the links made, say, by the original author, and a
'private' linkbase may contain links made by the individual user. This ensures
that private annotations and links are not visible in the public system.
Show Links
Since not all link anchors are buttons, no buttons in the text may
appear, especially if the user is not reading using the fully-aware text
viewer. Under these circumstances it may be of interest to know what links are
still available. If the user selects a piece of text and uses the Show Links
action, the system will send every word in the text and every pair of
consecutive words in the text through the filter chain as if they had been
individually selected and then follow link had been selected. The result is
that all possible links from the selected text will become available to
follow.
Navigational Filters
There are two further filters which are of particular interest in aiding
navigation. The History mechanism is a filter that keeps a list of all
documents that have been visited and allows the user to return to a particular
document. Histories may be saved at the end of a session. The Mimic filter
allows the user to follow a pre-defined tour through the documents. It has the
feature that all the normal Microcosm actions are still available while
following a mimic. This means that the user may branch out from the
pre-defined tour at any time, while still being able to return to the tour
whenever required.
The Document Management System
Microcosm must know about the documents in the system. The Document Management
System (DMS) is responsible for maintaining data about these documents and the
attributes of these documents. Typical attributes are an English description of
the file, the full filename, the physical and logical types of the document and
the projects into which the document is already linked: other attributes are
allowed such as authors and keywords, and further attributes may be user
defined.
The DMS provides two services: firstly it provides a safe method for moving the
physical position of documents without having to change all the linkbases;
secondly it provides a method for accessing documents by their attributes. For
example, it is possible to make Boolean queries based on attributes such as
keywords in much the same way as one queries an on-line library catalogue.
Implementations
Currently Microcosm is implemented within Microsoft Windows. Versions of
Microcosm are under development for Apple Macintosh computers and for UNIX
machines running X-Windows.
Microcosm Research Team :
Wendy Hall, Hugh Davis, Ian Heath, Gary Hill, Rob
Wilkins, Zhuoxun Li, Nick Beitner, Andy Lewis, Mylene Melly, Simon Knight, Mark
Weal, Rupert Hollom
for information contact Hugh Davis: tel 01703 593669
Microcosm Support &; Development Team
Roger Rowe, Jon Russell, Richard Underwood, Oliver Dewdney
For information contact Roger Rowe: telephone
(01703) 594490 e-mail rr@ecs.soton.ac.uk
For technical support: telephone
(01703) 593669 e-mail mcm@ecs.soton.ac.uk
Details of Applications Developed using Microcosm can be obtained from the
Scholar Project at The University of Southampton Interactive Learning
Centre
Su White, Pat Maier, Kate Dickens, Simon Morice, Erica Ferry
for information telephone (01703) 593315
Further information can also be found at the following web addresses:
http://ilc.ecs.soton.ac.uk/
http://bedrock.ecs.soton.ac.uk/Micrcosm/
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