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How
the Science of Artificial Intelligence
Shapes Knowing
EDUC 800, Ways of Knowing, April 25, 2001
Introduction
Of all the ways the human mind has of knowing something – and
by knowing, we mean a shared, valued process of getting to a collective
truth – the science of Artificial Intelligence (AI) has proven
to be the among the most enigmatic. Bursting onto the scene a few
years after the end of World War II, AI quickly established itself
as what Kuhn (1962) calls “normal science”, and for nearly
a quarter of a century, defined the scientific process to a collective
set of truths about the boundaries of human intelligence versus machine
intelligence.
There is no single, agreed-upon definition of Artificial Intelligence.
However, Finlay and Dix (1996) offer a working definition when they
note that “AI is concerned with building machines that can and
react appropriately, adapting their response to the demands of the
situation, and displaying behavior comparable with that considered
to require intelligence in humans.” (p. 2). At first, AI appeared
to be an excellent illustration of Kuhn’s paradigm dialectic.
After establishing itself in 1970 as “normal science”,
AI encountered anomalies in the 1980s that sparked a crisis in the
field that generated alternative theories of intelligence. Unlike
Kuhn’s dialectic, however, no best alternative has ever appeared
to replace the old AI paradigm and become the “new” normal
science. Instead, those alternative theories generated their own crises,
which in turn generated even more theories. The end result –
at least, the result as it looks in 2001 – are three collective
sets of truths, each with their own “normal science” status,
recognized by the scientific community, co-existing and shaping knowing
in their own way. Yet, each sits “comfortably” under the
umbrella name of Artificial Intelligence. The purpose of this paper
to describe ...
• how AI initially began to shape knowing
• why the response to anomalies and crises did not follow the
typical paradigm dialectic, and
• how – in a reverse loop of the dialectic - knowing is
currently shaping AI.
AI Shaping Knowing: The Road to “Normal Science”
Between 1945 and 1950, scientists who had worked with wartime calculating
machines began to re-examine the use of computers for peaceful purposes.
Two groups of innovators emerged, each with its own vision of the
potential of computers and each with its own research program. The
first group, led by Herbert Simon and Allan Newell, started from the
premise that the human mind and the computer are two different instances
of a single species of device: a device that generates intelligent
behavior by manipulating symbols using a set of formal rules grounded
in the mind’s representation of the world (Simon 1996). For
Simon and Newell, problem solving was the paradigm of intelligence.
As such, science should flesh out the mind’s representations,
so that the computer can be programmed with the appropriate sets of
rules to carry out the desired behavior.
The other group, led by Frank Rosenblatt, started from the premise
that learning is the paradigm of intelligence. Drawing upon the principles
of neuroscience, this group believed that science should attempt to
automate the procedures by which a network of neurons learns to discriminate
patterns and respond appropriately. Computers should be used as a
medium for modeling the human brain. Dreyfus and Dreyfus (1988) summarize
the differences between the two groups as follows:
Another way to put the difference between the two research
programs is that those seeking symbolic representations were looking
for a formal structure that would give the computer the ability
to solve a certain class of problems or discriminate certain types
of patterns. Rosenblatt, on the other hand, wanted to build a physical
device, or to simulate such a device on a digital computer, that
could then generate its own abilities. Both approaches met with
immediate and startling success. (p. 18-19)
By 1956, Simon and Newell had successfully programmed a computer
using symbolic representations to solve simple puzzles and prove theorems.
They also predicted that computer “intelligence” would
exceed that of humans. In an article in the Jan.-Feb. 1958 issue of
Operations Research (as cited in Dreyfus and Dreyfus 1988), Simon
and Newell state that “intuition, insight, and learning are
no longer exclusive possessions of humans: any large high-speed computer
can be programmed to exhibit them also.” (p. 19). Rosenblatt
had also put his ideas to work by building what he called a perceptron,
an information processing automaton constructed as an analogue of
the biological brain, and presented as empirical evidence of the feasibility
of human cognitive functions in computers. At Dartmouth College that
same year, John McCarthy called together the world’s foremost
logicians, computer scientists and cybernetics technicians involved
in the design of automata, to launch the idea of Artificial Intelligence
(AI).
By 1970, the brain simulation research group began losing ground.
Although both groups had discovered that as problems got more complex,
the computation required by both approaches would grow exponentially
and soon reach intractable proportions, funding for brain simulation
research all but dried up. There have been a variety of reasons offered
as to why the brain simulation group failed, ranging from conspiracy
theories about MIT researchers Papert and Minsky trashing their competitors
in a book, to flaws in the biology- and psychology-based neural nets
that were the foundation of brain simulation. However, Dreyfus and
Dreyfus (1988) have a very valid point when they note that Simon and
Newell’s physical symbol system more closely resembled the rationalist/reductionist
tradition in which all scientists were accustomed to working. In other
words, the physical symbol system approach more closely resembled
the “normal science” tradition than did the holism of
the brain simulation approach.
Returning to Kuhn’s (1962) definition of “normal science”
as “research firmly based upon one or more past scientific achievements
that some particular scientific community acknowledge for a time as
supplying the foundation for its further practice”, the paradigm
of Artificial Intelligence defined by Simon and Newell is an excellent
fit. It was sufficiently unprecedented as to attract an enduring group
of adherents away from competing modes of scientific activity (brain
simulation), and was sufficiently open-ended as to leave much to be
resolved. Thus, from 1955-1965, Simon and Newell focused on the research
themes of representation and search to show how a computer could solve
a class of problems using the heuristic search principle of means-end
analysis, then incorporated this principle into their General Problem
Solver (GPS). The GPS was based on substantive rationality, an intelligent
system’s adjustment to its outer environment, and procedural
rationality, an intelligent system’s ability, through knowledge
and computation, to discover appropriate adaptive behavior. Simon
then applied the GPS to decision-making theory, in which the decision-makers’
way of knowing how to make the best decision is grounded in finding
a good course of action through selective search. This approach to
decision-making still informs most of corporate decision-making.
From 1965-1975, Papert and Minsky at MIT focused on
what facts and rules to represent in order to develop methods for
dealing systematically with “microworlds”. Computer programs
such as SHRDLU, which could follow natural language commands (Winograd
and Flores1986) were examples of the several stellar outcomes of AI.
As we shall see in the next section, however, its “normal science”
status was rather short lived.
Breakdown in the Science of AI: Anomaly
Leads to Crisis
In the previous section, I mentioned Papert and Minsky’s pursuit
of methods to deal systematically with knowledge in isolated domains
called “microworlds”. The intent was to make these microworlds
more realistic and combined in order to approach real-world understanding.
However, efforts to build various data structures of representation
yielded little result. Repeated failures would soon turn the anomaly
of representation replication into a full-blown crisis. It appeared
that the microworlds approach could not be extended to the real world,
creating what Kuhn (1962) called the sense of “malfunction”
that is a pre-requisite to crisis and to paradigm shift.
While AI was wrestling with the representation of knowledge, developments
in biology, psychology and philosophy theories began to challenge
the core concept upon which physical symbol systems-AI was based:
namely, that the objective world of physical reality and the subjective
mental world of an individual’s perceptions are two separate,
but combinable domains. Noted AI researchers Terry Winograd (the author
of the natural language SHRDLU program discussed in the previous section)
and Fernando Flores began to questions AI assumptions openly. Just
as Papert and Minsky’s book had torn down the foundations of
Rosenblatt’s brain simulation research some twenty years earlier,
Winograd and Flores’ book (1986) attacked the physical symbols
system approach, to which they had been key contributors. However,
they did so by drawing upon the research from the physical and social
sciences to substantiate their attacks, particularly the work of Gadamer,
Heidegger, and Maturana.
The common thread among Gadamer, Heidegger, and Maturana
is the emphasis on the social and environmental context of human knowledge,
with the “microworlds” merely instances of a shared whole
of common human concerns. Winograd and Flores summarize Gadamer’s
discourse on language and tradition (the hermeneutic circle) and knowing
when they state, “what we understand is based on what we already
know, and what we already know comes from being able to understand”.
(p. 30). They go on to review Heidegger’s rejection of the concept
that the objective physical world is the primary reality, and also
of the concept that an individual’s perceptions are the primary
reality. Instead, Heidegger argued that it is impossible for one to
exist without the other, and that objects and properties are not inherent
in the world, but arise only in an event of “breaking down”
in which they become “present-at-hand”. They summarize
Heidegger’s point, stating “what really is is not defined
by an objective omniscient observer, nor is it defined by an individual
but rather by a space of potential for human concern and action.”
(p. 37). Winograd and Flores also draw upon Maturana’s account
of linguistic domains - which emphasizes social structure rather than
the mental activity of human individuals as the foundation of human
action – as further evidence of the common sense knowledge problem
of AI.
Clancey (1997) also cites Winograd and Flores’
book and the rise of the connectivist view of the perceptual and physical
worlds as heralding the era of questioning of the underlying assumptions
of AI. Although Winograd and Flores were not the only AI defectors,
they were the best known. Thus, the defection of two authoritative
sources severely challenged how AI had been shaping knowing. In an
earlier work on AI and cognitive science, Clancey (1991) summed up
the main error of AI as supposing that “the interpretation of
a representation is known prior to its production. But the meaning
of a representation is neither pre-definable nor static; it depends
on the observer.” (p. 57). In short, the “normal science”
of AI was experiencing what Heidegger called “breakdown”,
an interruption to the shared, valued process of getting to the collective
truth as defined by the physical symbols systems approach to AI.
The crisis in AI bubbled on well into the 1990s and
still exists today, spurring a variety of alternatives to the physical
symbols system paradigm. In a review of the prevailing philosophical
and technical criticisms of AI, Sterling, Beer and Chiel (1991) note
that the AI crisis included ideological perceptions ranging from total
denunciation of the science of AI (Winograd and Flores), to a feeling
of malaise (McDermott), to a denial of any problem (Hayes). Technical
criticisms ranged from connectivism (Smolensky), to a new approach
to problem definition (Brooks), to the focus on open systems (Hewitt).
None of these alternatives has succeeded in acquiring the collective
consensus required to adopt a “best alternative” and move
the paradigm dialectic along to a replacement of physical symbol systems
“normal science”. Moreover, there have been spectacular
successes with high-speed symbol manipulation by knowledge-based expert
systems. Clancey (1997) draws particular attention to two successes
of the early 1990s. One such success is MYCIN, a program that assists
physicians in diagnosing certain types of bacterial blood infections
and to determine suitable treatments. The success of MYCIN and other
expert systems lies in their ability to make decisions based on thousands
of “if-then” logic rules grounded in knowledge gleaned
from leading authorities in the field. Another success is Cohen’s
“artist” AARON a robot that is able to draw pictures of
humans based on this same type of logic pre-programming. These successes
have spawned further research of situated robots, with the objective
of developing a theory of spatial learning without pre-defining categories
in the architecture of the robot. Aiming for gradual measurable success,
robot research is now focused on insect and animal behavior. Clancey
sees this “downsizing” in the focus of expert systems
as a victory, not a defeat:
The combination of the synthetic approach, focusing
on simple animal behaviors, a dynamic-interactive perspective, and
a selectionist mechanism, has breathed new life into AI research.
Instead of equating intelligence with the ability to use descriptive
models, we are now examining mechanisms by which a machine can explore,
categorize and survive in an unknown environment. Having arrived at
the problems of learning new features and coordination memory, the
point of view that all knowledge can be captured, packaged, and disseminated,
which drove the design of systems like MYCIN, appears narrow and arcane
– this is progress! (p. 171).
Nevertheless, there have been no successes where computers
have matched human flexibility over wide domains or in tasks requiring
“common sense” knowledge. Consequently, AI has fragmented.
In addition to physical symbols systems AI has been joined by low-level,
microscopic biological models of AI, each with their own approach
to shaping knowing and some having found successful practical applications.
Munakata (1998) describes this second category of AI as including
the following paradigms: 1) neural networks, offering computational
models of the brain; 2) genetic algorithms, offering computational
models of genetics and evolution; 3) fuzzy systems, a technique of
extending concepts to a continuous paradigm, especially for traditionally
discrete disciplines; 4) rough sets, a technique for mapping data
and discovering relationships in the data. These have served as the
theoretical foundation of contemporary data mining software systems;
5) chaos – non-linear deterministic dynamical systems that exhibit
sustained irregularity and extreme sensitivity to initial conditions.
Fractal Geometry is the most well know practical application of Chaos.
Future Trends/Directions
Few if any in the field of Artificial Intelligence still adhere to
the notion that computers will one day be superior to humans. Although
there is the potential for the type of havoc wreaked by HAL in Kubrick’s
2001: A Space Odyssey, humans will do exactly what Astronaut Dave
did to HAL. As stated so well by Gillies (1996):
If a computer fails to do what its human controllers
want it to do, it will, of course, promptly be switched off and reprogrammed
so that it does perform its assigned task correctly. This situation
puts humans in a position of power and dominance vis a vis computers,
and it is this which renders humans superior to computers. Human superiority
to computers is, one might say, a political superiority. (p. 152)
Nevertheless, there is no consensus as to what the future
of AI really is. Finlay and Dix (1996) focus on the differences between
the human mind and the computer, noting that the computer performs
poorly in those areas in which the human mind works well (creativity,
flexibility, and learning), but perform well in those areas that exceed
our mental capacity (memory, speed, and accuracy). Aiello and Nardi
(1991) believe that AI is still in the process of becoming a well-defined
science, while Flach (1991) contends that AI should now concentrate
on the realization of intelligent skills on a computer.
In recognition of the finite nature of funding, Michalski
and Lithman (1991) propose that future AI research address the following:
1) how to implement common sense and plausible reasoning; 2) how to
develop powerful learning capabilities that are able to take advantage
of all kinds of prior knowledge and to explain to humans what was
learned; 3) how to introduce and organize large amounts of human knowledge
in machines and how to update or improve that knowledge in the process
of its normal use, and; 4) how to recognize objects and concepts from
incomplete, variable and context-dependent cues. Karakash (1998) advocates
using AI research to evolve and refine our understanding of the concept
of intelligence, stating that “the notion of natural (human)
intelligence has turned out to be dependent on AI. The proof is that
progress in the latter constantly incites us to redefine the former.
In the AI mirror, the concept of intelligence has become labile, as
if the object of our study changed with our research.” (p. 23).
In assessing the lack of consensus about the success of AI –
other than in expert systems and computer games – Chapman (1991)
concludes the following:
That AI has no criteria for resulthood of its
own, and must make do with those inherited from other fields, is part
of what makes it hard to evaluate AI research, and part of the reason
AI is fragmented into mutually incomprehending schools. (p. 214).
Implications for Learning and Knowing
AI as a discipline providing engineering techniques to solve difficult
problems in concrete, well-defined application areas has had measurable
success. AI as the study of the nature of intelligence and how to
reproduce it has been a clear failure. Where the jury is still out
is with AI as a means of gaining insight into the nature of human
intelligence and learning, rather than as a replica of these. In this
area, AI-based agent technology appears to offer a great deal of promise
in dealing with the challenges of the 21st Century learning environment.
Agent-based tutoring systems have had the most success to date. O’Riordan
and Griffith (1999) see the rise of intelligent agents as an attempt
to overcome the lack of support for peer-peer learning, the static
nature of course content, and the lack of support for personalized
learning in web-based education. In programming intelligent agents,
Kurhila and Sutinen (1999) note the importance of leaving the responsibility
of the pedagogics of the material to human experts creating the learning
material. Albrecht, Koch and Tiller (2000) have developed a web-based
teaching system that takes into account the spatial and mental abilities
of learners by incorporating a great deal of user-system interactivity.
Some AI applications to educational systems are constructivist in
approach, all focus on collaborative learning.
Although finite funding resources remains an issue for
AI educational applications, early successes have kept the funding
faucet open. However, research in and applications of AI in education
have fallen under the Instructional Technology umbrella, with some
researchers refusing to associate themselves with the term Artificial
Intelligence. However, it is not yet determined as to what extent
these educational applications will lead to either new AI paradigm
alternatives or to a “best alternative”. Until then, AI
will remain what Ratsch and Stamatescu (1998) call “transdisciplinary,
nomadic, if you will, its followers stretching out behind as it migrates
from one territory to another, with conceptual or technological breakthroughs
in one area providing feedback for all the others.” (p. 25).
References
Albrecht, Florian, Koch, Nora, & Tiller, Thomas. (2000). SmexWeb:
An adaptive web-based hypermedia system. Journal of Interactive
Learning Research, 11 (3/4), 367 – 388.
Baylor, Amy. (1999). Intelligent agents as cognitive tools for education.
Educational Technology, 39 (2), 36 – 40.
Chapman, David. (1991). Vision, instruction and action.
Cambridge, MA: The MIT Press.
Clancey, William J. (1997). Situated cognition: On human knowledge
and computer representations. Cambridge, UK: Cambridge University
Press.
Devedzic, Vladan, Jerinic, Ljubomir, & Radovic, Danijela. (2000).
The GETS-BITS model of intelligent tutoring systems. Journal of
Interactive Learning Research, 11 (3/4), 411 – 434.
Dreyfus, Hubert L. and Dreyfus, Stuart E. (1988). Making a mind versus
modeling the brain: Artificial Intelligence back at a branchpoint.
Daedalus Journal of the American Academy of Arts and Sciences,
Winter 1988, 15 – 41.
Finlay, Janet & Dix, Alan. (1996). An introduction to artificial
intelligence. London: UCL Press.
Flach, Peter A. & Meersman, Robert A. (Eds.). (1991). Future
directions in artificial intelligence. Amsterdam, The Netherlands:
Elsevier Science Publishers.
Gillies, Donald. (1996). Artificial intelligence and scientific
method. New York: Oxford University Press, Inc.
Kurhila, Jaako & Sutinen, Erkki. (1999). Sharing an open learning
space by individualizing agents. Journal of Interactive Learning
Research, 10 (3/4), 287 – 300.
Munakata, Toshinori. (1998). Fundamentals of the new artificial
intelligence: Beyond traditional paradigms. New York: Springer-Verlag
New York, Inc.
Ranwez, Sylvie, Leidig, Torsten, & Crampes, Michel. (2000). Pedagogical
ontology and teaching strategies: A new formalization to improve lifelong
learning. Journal of Interactive Learning Research, 11 (3/4),
389 – 410.
Ratsch, U., Richter, M.M. & Stamatescu, I.-O. (Eds.). (1998).
Intelligence and artificial intelligence: An interdisciplinary
debate. Heidelberg, Germany: Springer.
Simon, Herbert A. (1996). The sciences of the artificial.
Cambridge, MA: The MIT Press.
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