Computing as
a compensatory tool
Human information processing processes
have their limitations. How might the computer
compensate for these? Three aspects of human cognition underline the attractiveness of human-
computer collaboration:
Memory The limited
capacity of short-term memory is, of course, the primary constraint on the
human cognitive system The capacity of short-term memory has been estimated at
approximately seven chunks (plus or minus two) by Miller (1956), and approximately five
chunks by Simon (1974). A chunk is a semi-elastic unit whose size depends on the familiarity
and meaningfulness of the information to the individual. This, in turn, is dependent on relevant
prior knowledge (knowledge structures) in long-term memory.
Organisation of knowledge To remain immediately available, information in short-term
memory must be continually refreshed and rehearsed. But this rehearsal of information
competes for limited memory capacity with new information that comes along and with
information retrieved for current use from long-term memory. As a result, information in short-
term memory is lost or distorted as new information is obtained and capacity is reached. If all
the information needed at a particular time is not available in accurate form or cannot be
obtained from the environment or from long term memory, learning will not take place, or,
worse, mislearning might occur.
Not all information that passes through short-term memory is stored in long-term memory. This
is time dependent: Simon (1974) estimates that it takes between 5 and 10 seconds to fixate
each chunk in long-term memory. Once fixated, the retrieval or activation of information in long-
term memory is dependent on its structure and organisation, i.e. its interconnection with other
information. Information stored in computer memory is not subject to any of these restrictions.
Strategies Much of what goes on during learning is determined by the cognitive strategies
the
learner uses. These are the actions of the learner that obtain additional information (either from
environmental cues or associations, or from long-term memory), manipulate it, and organise
and structure it so that it enters long-term memory in a retrievable form. Cognitive strategies
include scanning, searching, questioning, chunking, hypothesis generation, decision making, etc.
The use of these strategies is based on the learners' perceptions of the task, the value they
place on it, and the assessment of their own performance. These processes are automatic for
some people, but they are not automatic for less efficient or less experienced students. For the
latter, decisions about processing of information occupy and compete for limited space in short-
term memory.
Support
|
|
|
|
|
1. Technologies
