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The
components of access
The access chain
The systems that affect access to learning can be considered as
links in a chain, with the proverbial caveat that the system is only as strong
as its weakest link.
Elements of the infrastructure systems that affect access to
learning are outlined below. These systems are quite complex, but basic
explanations of the various players' roles, including those "behind the
scenes", are needed in order to understand how their decisions affect
educational access.
The four levels of access
Let us begin the tour with a fairly familiar example. Canadian
educators have been using print based correspondence courses since shortly
after a postal system was established. This example demonstrates an important
structural feature of access provision: that four levels of systems must
function effectively in order to have genuine accessibility: national
infrastructure, educational provider, community, and the individual.
In this case, there needs to be a reliable postal system (the
infrastructure level): an educational provider willing to offer a course by
correspondence (the institutional level): reasonable access to a post office
for the learner (the community level): and a learner whose situation permits
enough time to study, light to read by, and so on (the individual level).
Whether learning opportunities are provided using some of these "old"
technologies or much newer technologies, these four levels continue to be
significant for considering access.
Considering each of these levels in turn, we can examine how
each of them relates with learning technologies, old and new.
The infrastructure
The basic transportation and communication infrastructures
established during the past century are still factors in access to learning, as
well as to many other services. For example, those who travel to class depend
on reliable transportation, whether by private car or public systems, and
conditions that permit safe travel in most weather, such as well maintained
roads, Those that study at a distance rely on postal or courier systems to
deliver materials intact and on time, and on the telephone system to contact
their instructor, the library, the bookstore and other learners.
Newer learning technologies require more from the
infrastructure. For example, while the use of audio conferencing to transmit
voices requires only one regular telephone line, the addition of computer
generated graphics requires the addition of one or more lines, or more
"bandwidth" on a telephone transmission system.
Bandwidth: An Explanation
Because the concept of bandwidth is quite significant to this
discussion, here is a brief explanation, from A. W. Bates:
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The more information that has to be transmitted, the more
capacity or bandwidth is required. One analogy is to think of messages as tiny
collections of sand, or "bits" of information. If a bit of information has to
be sent quickly, a wide "pipe" is required. The same amount of information can
be sent through a thinner "pipe" more slowly. Thus, telecommunications capacity
is a combination of bandwidth and speed of transmission.
The bandwidth required depends on the application. Thus,
data, such as letters or numbers, which singly do not carry a great deal of
information, can be sent using a narrow bandwidth and at relatively slow
speeds. Sounds, such as speech on the phone, contain more information than the
printed word, and have to be carried as the same speed as normal speech for a
conversation to be possible. A photograph or image can also be digitized, and
carries more information than a page of text... Colour requires a great deal
more bandwidth than black and white images. The greater the amount of
information, and the faster it needs to be sent, the greater the bandwidth
required. 9 |
Many of the newer technologies require a significant amount of
bandwidth. For example, most videoconferencing requires transmission lines with
significantly more capacity than an ordinary telephone line, depending on the
system and the quality of the image being transmitted. As well, computer-based
material that has extensive graphics and complex structures, such as much of
the material on the World Wide Web, can take a significant time to transmit,
depending on capacity of all the systems involved, from the telephone system to
the Internet provider's system, to the modem and line capacity of the user.
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