Conjectural Dogma and its Revision [Karl Popper]
Karl Popper
Although many great scientists such as Albert
Einstein, Jacques Monod and Sir
John Eccles have publicly acknowledged their debt to Popper, for
presenting the ultimate scientific method, his work is still not fully
accepted by science. It is especially ignored by the science of
learning, where it should be making a considerable impact. Today
scientists and school children still have to struggle with the concept
of induction, even though, Karl Popper has shown that induction does
not exist and is in fact a misunderstanding of how learning takes place.
Francis Bacon.
Induction is the inferring of general law from
particular instances and it was developed as a methodology of science
by Francis Bacon.
Francis Bacon, saw it as a way of understanding nature in an unbiased
way, as in his view it derived laws from neutral observation.
It found easy acceptance because ordinary people
found it comforting. It seemed to be an integral part of how our brains
work, and so it was, the primitive animal part. Why do I say that?
Because any animal with a brain can form a conjecture from a series of
instances. To be fair to Bacon his method did include a testing phase,
but this was seen as a way of verifying results and not as a way of
trying to see if the results were false. Indeed before Bacon nobody had
tried to put down principles of how science should proceed and thus
pseudoscience existed on equal terms with science. Even scientists as
eminent as Newton worked with both pseudoscience and science. What
Bacon came up with was a real improvement as far as scientific method
was concerned because such a method essentially did not exist before
him.
Induction.
Inductive argument, starts with the details of observation which
anchors persuasion in reality. It starts from immediate sensory data of
what can be seen and touched and then moves to the big picture of
ideas, principles and general rules. Starting from the small and
building up to the big can be less threatening than starting with the
big stuff. Scientists came to believe they could create scientific laws
by observing a number of phenomena, finding similarities and deriving a
law which explained all the observations. However, the rules of
induction seem "rubbery": they concern generalization of the "all" from
the "some", and involve evidence, probabilities and best explanations -
which can be wrong, even when the evidence is true. Inductive arguments
are always open to question as, by definition, the conclusion is a
bigger bag than the evidence on which it is based. Conclusions can be
wrong if observations are faulty or are drawn from an unrepresentative
sample. More importantly inductive conclusions can be wrong despite any
number of observations, because there is no way every instance can be
examined. How many ravens were seen to be black, before a white one was
seen in Japan? How many white swans were seen, before a black one was
seen in Australia?
Supporters
of induction such as John Stuart Mill would tell us that all "general
facts" are based on induction and that therefore deduction and logic
cannot even begin until there have been observations and something has
been induced from them. Supporters will tell us induction lies at the
root of the scientific method that has done so much to advance humanity
in the last 500 years. They will say properly applied scientific method
is inductive reasoning in its purest form. They will say that the core
of inductive reasoning is the ability to look at outcomes, events,
ideas and observations, and draw these together to reach a unified
conclusion.
Theory
comes first.
Popper points out, that the above, is not the commonsense, it at first,
seems to be. Popper suggests rather, that we are indeed unable to even
begin to make observations, if we do not have a theory. Without theory,
he suggests that all observations are random, and therefore
meaningless. Further it follows that if we already have a theory, we
are better off trying to disprove the theory rather than verify or find
additional evidence for it. Popper thus, provided us with a better way
of proceeding in science. It is better because it leads us away from
looking for positive examples and makes us look for negative examples.
Instead of looking for what fits in with our pattern we are forced to
try and find ways in which the pattern could be broken. By creating a
hypothesis and testing it, we open our theory to the possibility of
being wrong. Thus we abandon the straight forward, untested idea of
induction.
Some
sciences seem to profit from the idea of Induction.
It is true that some sciences such as archeology and biology tend to
involve the collection of many observations without much in the way of
theory being formed. But they are still guided by theory, even if it is
theory that has been held for many many years. It is in such sciences,
that little in the way of disproving theory can be undertaken or
expected. People working in such sciences may well be helped in an
accumulative process, by what they understand to be induction. However,
as rigorous scientists they would not be indulging in outlandish
claims, but rather letting their observations speak for them. This
method of proceeding in science has worked for 500 years and this site
does not wish to tell scientists they cannot use it. However, it seems
that induction, unconstrained by scientific rigor, can lead us far
astray. The ordinary person does not understand the tentativeness with
which apparent induction has to be approached, but usually thinks he
understands it very well indeed.
Human brains and the curse of induction.
The problem with induction is that we want it to exist, we want it to
work. Why is that? Well, our brains have evolved into mechanisms for
scanning the environment for patterns that may be true. We want those
patterns to turn out to be true, because this is part of the primal
functioning of the brain. Our ability to prove things wrong developed
later, and we use it mostly for trying to prove others wrong, not
ourselves. But any good scientist knows, that any theory that is to be
taken remotely seriously is one that has been rigorously tested, one
that has run the gauntlet of those who would prove it false. So a
theory is not validated, it is instead, that we are unable to
invalidate it or disprove it.
Snake
oil, Erich Von Daniken and Dan Brown. Induction can be used,
and has been used, in ways that are in keeping with rigorous scientific
methodology, but induction is not used that way in everyday life by the
man in the street. Suppose ten people tell us that snake oil cured them
of something. Suddenly we want to believe snake oil is a cure all.
Snake oil has not been tested in any way but we want to believe anyway.
Erich Von Daniken writes a book called "Chariots of the Gods"
documenting ancient marvels and suggesting it could be the work of
aliens and suddenly thousands of people want to believe and do believe
that aliens have visited Earth in the distant past. Never mind all the
other explanations for Von Daniken's drawings and structures, it is a
good story and we don't want it to be proved wrong. Stranger still, Dan
Brown writes a book called the "Da Vinci Code" and suddenly people want
to believe in a conspiracy by the Catholic Church to suppress the love
life of Jesus Christ. Brown professes no evidence at all, no instances
other than the imaginary ones in his novel, yet still people believe.
Alien abduction.
A person has a dream about aliens abducting them, they meet with other
people who have had similar dreams, and suddenly the group starts
believing they have been abducted by aliens. Never mind all the other
explanations for their experiences, just dreams, hypnagogic (the
intermediate state between wakefulness and sleep that precedes sleep)
imagery and hypnopompic (the intermediate state between sleep and
wakefulness that precedes full wakefulness) imagery. Dreamlike images
can seem very real when experienced in these half wakeful states. Also
do not forget people inevitably exaggerate their experiences to make
them more interesting, and some people just plain lie to get attention.
The point is, that even a thousand instances of people believing they
were abducted mean nothing, if the experiences cannot be tested.
Induction fools us again and again, because we are so busy trying to
prove ourselves right, that we do not try to prove ourselves wrong.
Deferring
to authority. Part of the problem is that most of our
learning is done by listening to and reading the words of others and
very little is done though designing and and executing tests of
existing theories. Thus we always have to defer to the authority of
those others. That's fine, but how do we know what is authoritative and
what is not? Can we be sure the books we learned from at school were
authoritative? No we can't. But apart from the fact they are well out
of date when we leave school, they were probably mostly okay. But then
what? We are out in the world and suddenly there are best selling books
called "The Secret" or "Chariots of the Gods" and they look as
authoritative as any other. What about TV shows, or movies about the
destruction of the World Trade Center, or what we read in newspapers
and magazines. These media are trying to entertain us not educate us.
Expect the sensational not an examination of the truth of things.
How
does unchecked induction function? Let us look at the world
of quackery. The history of medicine is littered with charlatans,
because we have an inbuilt healing system in our bodies. Because of our
body's ability to heal itself, almost anything can be offered up as a
cure for an ailment, and probably has been. Our body heals itself, but
we give credit to some version of snake oil. Here's how it works. We
get sick. Someone we trust tells us about the healing power of say
crystals, or maybe we read about it somewhere. In any case, we decide
to try the crystals and lo and behold we get better. Amazing yes? No!
It is just a coincidence. Maybe our body healed itself, or something
else like medicine from a doctor did the trick. Next time we get sick
we try the crystals again. This time the crystals do not seem to work.
We are sick for a long time, but we persist with the crystals until
finally we do get better. Wow, now the crystals have worked twice. We
are reading about crystals thousands of people give testimony that
crystals have worked for them. The evidence linking crystals with
healing was arrived at by an inductive process. We are only looking at
the positive instances. We are only noticing when crystals seem to
work. We are using a process of generalizing from the particular to the
general, but we are not trying to disprove the health giving properties
of crystals.
In
science we have to ask questions that are likely to lead to disproof,
such as the following: What about all the times when the crystals did
not work? Were we taking other medicine? How many times were these
other people cured with crystals? Could some of these other people be
lying or confused? How does crystallography fit in with what you know
about science? From these questions you can create a hypothesis and
build trials for finding conditions within which your theory either
appears to work or not work. The most effective way to use these trials
is to try and prove the theory wrong, while at the same time hoping it
does not prove to be invalid.
Ultimately
induction is useless in trying to make something scientifically
acceptable, if it is currently unacceptable to science. So much is this
so, that induction might as to well not really be considered to exist
at all. Yet the average person believes he uses it all the time, and is
fooled by it over and over.
Popper says in his book
"Unended Quest":
"As for induction (or
inductive logic, or inductive behavior, or learning by induction or by
repetition or by "instruction") I assert that there is no such thing."
"I suggested that all scientific discussion ["I
suggest learning" edit.] start with a problem
(P1) to which we offer some sort of tentative solution - a tentative
theory (TT); this theory is then criticized, in an attempt at
error elimination (EE); and as in the
case of dialectic, this process renews itself: the theory and its
critical revision give rise to new problems (P2)
Later, I condensed this into the following schema:
P1 -> TT -> EE -> P2,
a schema which I often used in lectures."
Learning without induction.
Popper shows that rather than perform a number of repetitions when we
are learning we, as thinking creatures, first conjecture a possible
solution to a problem. Then we either actively test it, as a scientist
would, or accept it till the events of life seem to corroborate it or
refute it. (Not only does Popper show that we create and revise
conjecture from analysis of sensory input, but that sensory input can
only be perceived through existing theory.) For our purposes all
learning should be understood to take this developmental form. The
psychiatrist Anthony Storr arrived at the following conclusion about
getting to know people:
"When we enter a new
situation in life and are confronted by a new person, we bring with us
the prejudices of past and our previous expectation of people. These
prejudices we project on the new person. Indeed, getting to know a
person is largely a matter of withdrawing projections; of dispelling
the smoke-screen of what we imagine he is like and replacing it with
the reality of what he actually is like."
Popper would agree with this, but would extend it
to getting to know about anything. He would also restrict it to
approaching a more realistic mental model of that thing, without ever
being able to know it completely. In other words, we can never truly
know reality, and we initially perceive it through the smoke-screen of
our previous conjectures. Popper often calls this smoke-screen dogma
because often, and particularly in the early learning of children,
these conjectures are considered to be true until invalidated. Also
this invalidation by critical error elimination comes with great
difficulty, and is usually not given up easily. While we are infants,
and to some extent all our lives, these conjectures (both the
conjectures that are tested and the conjectures not actively tested)
are understood as dogma, not as conjecture. That is to say, the
conjecture is totally accepted as being true. Unlike real dogma,
however, this kind of dogma can be and is, by force of inconsistency
with external events, subject to critical error elimination and is
eventually discarded.
"Every clarification breeds new questions."
Arthur Bloch
Popper proposes, that all learning occurs by
paring back our misconceptions and replacing them with more accurate
conceptions. He suggests this is true whether the work of scientists,
the actions of a new born child or any other thinking creature. Popper
insists that the creation of new conjecture comes about mostly as a
result of older conjecture being found inconsistent with incoming data
and thus refuted as part of error elimination. Thus a hole is left in
the learner's map of reality, which he tries to fill by creating new
conjecture, which then invokes new error elimination. This seems to
work, but a problem occurs if we go back far enough. Where does the
first conjecture or dogma come from? Popper explains this by suggesting
that all creatures are conceived with some inborn expectations. (For
humans very rudimentary instinctual expectations.) The beauty of this
is that the inborn expectations do not have to be valid, and are
immediately subject to error elimination and the formation of new
conjecture.
The discovery path. So
what does all this mean in terms of learning? It means that we start
off in life with a need for our world or environment to make sense and
be consistent. We try to make it consistent by forming conjecture as to
how it is consistent. We are then faced with two possibilities. We can
experiment to find the limits in which our conjecture will work by
finding where it does not work, or we can accept it till subsequent
events refute it. Either way it will eventually be subjected to
criticism and or error elimination.
The young child. How
then does this work for the young child? The young child is very
motivated to find consistency in his environment (his reality). He
forms conjectures, (dogmas) which lead him to have expectations of his
environment. He probably does not consciously try to prove himself
wrong but as his expectations are not fulfilled, his dogma is refuted
nevertheless. Therefore he must produce new dogma to provide him with
new expectations. Popper seems to believe, at this early stage it is
not necessary to explain how the leap from nothing to a conjecture or
dogma takes place. However, he implies that it is created out of a
need. We need something, we reach out for it; the needing provides the
explanation or conjecture. This is like saying, anything can be a
tentative solution, and that the first conjectures are little better
than random. Of course, later we can talk about guesses, intuition and
correlation, but these elements are probably not available to the young
child, who has not as yet developed a fully functioning map of his
reality.
If Popper is right in all this, and it is commonly
believed he is, it demonstrates a lot about how we learn and how we do
not learn. For a start, it indicates that we probably learn nothing at
all through repetition as such, and only learn by conjecture creation
and error elimination. When learning a foreign language for instance,
we will never really learn a word by repeatedly exposing ourselves to
it in conjunction with its equivalent in our own language. We will only
learn it by placing it in a number of contexts, and then proceeding
through error elimination to discover if it is acceptable in those
contexts. Let us look at what Popper says about learning in "Unended
Quest".
He says: "I
distinguished three main types of learning process, of which the first
was the fundamental one:
-
Learning in the sense of discovery:
(dogmatic) formation of theories or expectations, or regular behavior,
checked by (critical) error elimination.
-
Learning by imitation. This
can be shown to be a special case of 1.
-
Learning by 'repetition' or
'practicing', as
in learning to play an instrument or to drive a car. Here my thesis is
that (a) there is no genuine 'repetition' but rather (b) change through
error elimination (following theory formation) and (c) a process which
helps to make certain actions or reactions automatic, thereby allowing
them to sink to a merely physiological level, and to be performed
without attention."
Philosophy
Popper informs us that there are three worlds:
-
World 1 is the objective
world of reality. Popper believes in the
existence of this objective reality. He does not believe that objective
reality can ever be known. He suggests that we try to know objective
reality by erecting theories about it.
-
World 2 is the subjective
world within each individual. This
is clearly that which is formed in the mind, and is a map or model of
reality developed from the intermeshing of the theories we have about
reality. This is not the entire content of World 2 as it must also
include both invention and revision.
-
World 3 is the body of
knowledge held in common in books computers and other forms of media. This
is also a map or model of reality. Without world 3 we would be little
better than cave men, for world 3 is a vast intricate map that no human
could ever contain. It is our cultural heritage and more. It is the
greatest minds of the past opened up, criticized and allowed to spill
on to our own inadequate maps of reality, so allowing them to grow in a
way that would otherwise be impossible. Again this is not the entire
content of World 3 as it includes competing theories, problems,
criticism, and revision.
We should try to be clear about these 3 worlds and
how they relate to learning. If Popper is correct this explains a lot
about learning. Obviously learning takes place in World 2 inside each
individual. But only a small but important portion comes from direct
interaction between World 1 and World 2. The major interaction in
learning is between World 3 and World 2. Early learning involves much
more interaction between reality and the learner. Babies are
continually forming conjecture as to how the world works and testing
the limits within which it works. But as our personal maps of reality
become more complete, we begin to interact more and more with World 3.
World 3 enables us to begin to take in whole
theories formed by others, and try to fit them into our personal
cognitive structure. If the new theory does not contradict anything in
our model, we accept it and it is assimilated into that model. If it
does not fit, we may have to go back and revise our theories to enable
it to fit. This usually requires we return to interaction with World 1
and test the theories. Alternatives are possible but not usually
productive. We can refuse to accept the new theory from World 3, or we
can hold two mutually exclusive theories as being correct. If the
latter is used for predicting reality, inconsistency and even madness
can result.
Popper's major contributions have all been
concerned with this World 3 knowledge, especially how it comes into
being, and how we can know if it is accurate. Because World 3 is very
important to learning, due to World 2's interaction with it, Popper's
understanding of it is critical to understanding learning. When Popper
talks about knowledge, he means not the knowledge in individual minds,
and certainly not the knowledge in objective reality, but the knowledge
that has been placed in World 3. Let me try to distill Popper's
understanding of World 3 knowledge and how it works:
-
Theories cannot be verified
they can only be falsified or refuted.
Popper shows that no amount of corroboration can ever validate a
theory, but that a single instance of deviation can invalidate it. Not
only that, but the amount of corroboration does not even improve the
statistical probability that we are correct. As Bryan Magee points out
in his book
"Popper", if we have a theory that water boils at 100
degrees, we can obtain an enormous amount of corroborating evidence and
still be wrong. We could be wrong, if we put a lid on the container or
if we try it up a mountain. Worst of all, all the corroborating
evidence would never have led us to doubt, let alone replace our
original theory.
-
At a methodological level
theories can not be falsified or refuted unless we formulate them in
such a way as to show just how they could be refuted. This
is because everything is subject to question; observation, definition
etc. By constructing hypotheses that are testable, we allow that they
may be wrong, and lay out how they may be refuted. However Popper goes
on to show that theories can be immunized against criticism, by the use
of a testable auxiliary hypothesis. When it was found that Newton's
gravitational laws concerning the motion of the planets were not
exactly obeyed in the movement of some planets, it could be said that
the theory of gravitation in planetary movement was disproven. However
an auxiliary hypothesis of the existence of an, as yet undetected
planet immunized the theory. The theory was completely returned to it's
previous status when a planet was discovered in the exact position
required by the hypothesis. So even if a theory was formulated so as to
clearly indicate how it could be refuted, the possibility exists that
even if it was refuted, this need not necessarily be permanent as it
could still be rescued.
-
We should therefore as an
article of method not evade falsification or refutation.
Instead we should formulate and present our theories as unambiguously
and clearly as possible, to invite falsification or refutation. All
knowledge is provisional and each theory must not only carry the seeds
of its own destruction, but also organize or prepare the way for that
destruction. On the other hand we should not abandon our theories
lightly, for this would involve too uncritical an attitude toward
testing, and would mean that the theories themselves were not tested as
rigorously as they should be.
-
A scientific theory is one
that openly exposes itself to testing.
Theories that explain things without providing any way of being tested
are unscientific and metaphysical or mythical in nature. A scientific
theory must be testable, but a good theory formulated as an hypothesis
will pin point where it can be disproved and how this may be tested.
-
Metaphysical theories are
not useless and should not be discarded on the grounds that they are
metaphysical. A theory that was at one
time not testable, and therefore metaphysical, may with changed
circumstances become testable and therefore scientific. A metaphysical
theory may not only be meaningful, but it may actually be correct. Our
inability to test it simply renders it unscientific. So if no
scientific theory can be created to explain some phenomenon we would be
foolish indeed to discard a metaphysical one. Indeed all science has
its roots in metaphysics.
-
Criticism is the tool for
determining if one theory is better than another. How
well a theory can withstand criticism will determine which theory we
hold to be the most correct or useful. Criticism may well be
instrumental in proposing useful or superior empirical tests. However a
theory's corroboration or refutation through empirical testing does not
end critical error elimination, for the testing itself is subject to
critical discussion. The out come of such discussion may be important
in making comparisons that result in one theory being held as being
preferable to another. Both scientific and metaphysical theories are
subject to this kind of evaluation. Theories which can not be
empirically tested may still be critically discussed, and have
arguments for and against them compared, as a result of which one of
them may appear preferable to another.
-
The importance of a theory
has a lot to do with the amount of informative content in that theory. If
we create a theory from which we derive a hypothesis stating that 1000
people will die, the information content of our theory is close to nil.
People die all the time so this statement tells us very little. If we
restrict our theory to say 1000 people will die in Singapore in the
next month we are beginning to have information content. If we theorize
1000 will die of AIDS in Singapore in the next month we have a theory
with high informative content but the probability that we are correct
has diminished. We can widen the theory to say that a 1000 people in
Singapore and 500 in China will die of AIDS over the next month. Our
theory now has even more informative content but has become even less
likely to be accurate. If two theories are put forward and empirical
testing is indecisive in supporting a preference for one or the other,
our preference should always be for theory with the greater informative
content. As the informative content of a theory increases, the
universality of its application, the amount of and usefulness of its
predictions or its accuracy will also increase if it is corroborated.
However the probability that it will be corroborated is in inverse
proportion to the amount of its informative content.
-
When a theory is refuted we
are challenged to form a new theory that incorporates much of the old
theory. Much of the old theory is
usually still confirmed and needs to be accounted for in the new
theory. In addition the evidence that has led to the refutation also
needs to be accounted for. This requires a leap of imagination on the
part of the creator, who takes it upon himself to invent something that
has not existed before yet explains more than was explained before.
-
If we are able to devise a
new theory which incorporates that which is still confirmed by the old
theory yet accounts for the anomalous instance, we will have created a
richer theory that produces more accurate and useful predictions. If
we return to Magee's example of the boiling point of water, we will
discover our new theory will tell us about the relationship between the
old situation at sea level or in open containers and enable us to
calculate differing boiling points for differing conditions. Our theory
has not reduced its informative content but rather increased it
considerably.
-
The growth of knowledge
(World 3) if approached in this way will be focused so it continually
approaches a more accurate approximation of what is the absolute truth
of reality. In other words we are being
asked to successively reinvent or reformulate a theory so it is each
time more inclusive than before. This approach propels us closer to the
universal truth. Though we know that we are continually drawing a more
accurate map or reality we must also understand that we can never know
if we have found it.
Prescience For Popper, it may
be said that the only difference, between the prescientific and the
scientific growth of knowledge, is that on a scientific level we
consciously search for our errors.
Science and permanence.
All theories, according to Popper, were simply to be held as having a
temporary possibility of being correct, until such time as they are
disproved. In Poppers mind there was no way of knowing which theory
would be flawed. So he deemed it best to hold they might all possibly
be flawed. Popper proposed an open society where no permanent truth is
held to exist. He held that in this way counter Ideas would be able to
emerge more easily.
Metaphysics and pseudoscience.
Popper spent a lot of time showing that much of so called science could
not be science at all. A lot of psychology, and political science could
not be rendered into hypotheses that could be tested. These so called
sciences simply could not be proven wrong and were therefore not really
scientific theories, but rather metaphysical theories. Popper admitted
that there may be some value in these theories but that there was no
way to have real confidence in them. Although Popper rejected
psychology and political science on the grounds they they were not
science, it is likely he would have approved of the rigorous scientific
experimentation being currently performed in social psychology. Popper
did not bother to attack other pseudo-sciences such as astrology much
as he undoubtedly thought these so self evidently flawed as to be not
worth the bother. In this he was probably wrong. It has now been fairly
well established through scientific test that humans generally are far
less logical than he thought, and prone to cling to induction, even
when no causal link can be produced.
Popper trusted in
reason. He believed in not just his own reason, but the
reason of others. He believed very little of worth could come without
criticism. He says:
"Faith in reason is not only
a faith in our own reason but also - and even more - in that of others.
Thus a rationalist, even if he believes himself to be intellectually
superior to others will reject all claims to authority since he is
aware that, if his intelligence is superior to others (which is hard
for him to judge), it is also only in so far as he is capable of
learning from criticism as well as from his own and other people's
mistakes and that one can learn in this sense only if one takes others
and their arguments seriously. Rationalism is therefore bound up with
the idea that the other fellow has a right to be heard, and to defend
his arguments."
Piaget
and Popper. Like
Popper, Piaget also found that the young child is motivated to find
consistency in his environment (his reality). Piaget talks about schema
or schemes by which he means a well defined sequence of physical or
mental actions (which in turn can be considered conscious or
unconscious conjecture in a dogmatic form). These schema or schemes
lead the child to have expectations of his environment. Piaget shows
that as his expectations are not fulfilled his schema or schemes are
found insufficiently adaptive and he must therefore revise or alter
these schema/schemes or create new ones to provide him with new
expectations. Popper and Piaget's ideas are clearly moving along
similar lines and we would be well advised to examine how these ideas
support each other and not emphasize the differences or the use of
different language.
The Open Society (Schools)
Popper, in his book
"The Open Society", tried to give some idea as to what a
society might be like if it was to optimize in favor of a structure
where his central thesis, critical error elimination, was paramount in
all aspects of that society. In the open society, and for this site's
purposes the open school, a forum of ideas is to be both encouraged and
individually criticized. Only in this way, Popper believed, can we
foster the ideas that promote the growth of knowledge, thus allowing
man to function more fully. In such a society the formation of theories
and the criticism of them would be encouraged to the fullest.
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