[LINK] Progressive display of electronic documents

[Tom Worthington]

Google announced last week that it was planning to trial 1 gigabit per 
second, fiber-to-the-home to between 50,000 and 500,000 people: 
<http://googleblog.blogspot.com/2010/02/think-big-with-gig-our-experimental.html>.

Google issued a request for information (RFI) for local government and 
the public: <http://www.google.com/appserve/fiberrfi>.

This was intended for the USA, but I sent a nomination for City Edge in 
Canberra anyway: 
<http://www.blogger.com/Google%20experimental%20fibre%20network>.

Much like Australia's NBN, suggested applications for Google's network 
are 3-D medical imaging for rural health clinics, downloading 
high-definition films and collaborative education with 3-D university 
lectures.

But faster networks will not necessarily produce a better Internet 
service. I suggest we need to design electronic documents, including web 
pages and videos, to display just what the user needs at a particular 
time. A by-product of this is that will allow a slower network to be 
used and allow networks to cope with congestion and faults better.

Providing more data to the user will not necessarily provide more 
information, it may just increase confusion with irrelevant details. For 
education, it is often better to provide a simple schematic diagram, 
rather than a high resolution image. Pushing data on students does not 
help them. The core materials for a 120 hour, 12 week university course 
can be a few hundred kilobytes of data, the equivalent of 100 pages of 
text (if efficiently encoded). There can be gigabytes of extra readings, 
audio and video, the students can explore, when the feel the need and 
can discuss with other students and the tutor. It is not providing large 
amounts of information which are important in these learning techniques, 
but that materials and people, are to hand when needed. In 
education-speak this is "mentored and collaborative learning", with some 
aspects similar to the Montessori method. One of the educational areas 
which further work is in teaching students how to cope with an overload 
of information.

Similarly in medicine, irrelevant detail does not necessarily help. My 
doctor does not look at the detailed imaging provided by MRI, CAT, 
ultrasound and other scans. They read the brief text reports prepared 
from these by specialists. It might make me feel better if they were to 
examine these in a 3D system and draw circles around areas using a light 
pen, but it would not improve the medicine delivered.

This can also apply with web pages. Providing a large complex document 
can overwhelm the reader, whereas a simple introduction and set of links 
to details can ease them into the topic.

One application where progressive display can help is with smart phones. 
These devices have small screens, slower links and distracted users. So 
providing large amounts of material does not help technically nor for 
the user. The current approach is to create special applications and 
documents for mobile users. I suggest we can redesign web documents to 
automatically allow for this.

One simple case is web images. The common web image formats (GIF, PNG 
and JPEG) all now allow for progressive image display. That is the image 
file is created so that a low resolution version can be displayed first, 
increasing in detail as more data is provided. These formats could be 
used by smarter web browsers to display images in the appropriate 
resolution for the display device and available bandwidth. Web servers 
can automatically convert images to progressive formats as required.

Another progressive technique is in the creation of web pages. Web 
designed web pages and web site allow the user to get an introduction 
and overview and then select more details. Most web pages will begin to 
render before all data has arrived. If the important information is at 
the top of the page, the user can select a menu option without waiting 
for the rest. The same can be done with some PDF documents. This can't 
be done with most ebook formats and you have to wait for the whole ebook 
to download before you can read any of it.

Some new video formats similarly allow lower resolution previews and 
streaming of the start of the video, without having to wait for it all.

These techniques could make the slower networks most of us will have for 
the foreseeable future more usable, without having to wait for gigabit 
networks. Even with gigabit networks, being able to get just the 
information you need will be a boon, without being overwhelmed with data.



-- 
Tom Worthington FACS HLM, TomW Communications Pty Ltd. t: 0419496150
PO Box 13, Belconnen ACT 2617, Australia  http://www.tomw.net.au
Adjunct Lecturer, The Australian National University t: 02 61255694
Computer Science http://cs.anu.edu.au/user/3890