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Title: Thomas%20Kuhn%20(1922-1996)

Thomas Kuhn (1922-1996) Paradigms, normal science
and revolution
Zoltán Dienes, Philosophy of Psychology
Paradigm Narrow definition Universally
recognized scientific achievements that provide
model problems and solutions to a community of
practitioners. (Paradigm is Greek for model,
pattern.) Broad definition The entire
constellation of beliefs, values and techniques
shared by members of a scientific community
(because they were all trained on the same
paradigm examples of good practice) E.g.
Newtonian dynamics.
Example in Psychology Behaviourism Narrow An
analysis of e.g. dogs salivating to a bell in
terns of classical conditioning provides a model
problem and solution Broad Beliefs and values
include Theories must only refer to stimuli and
responses, not internal states all learning can
be conceptualised as conditioning, etc
Normal science research firmly based on such a
paradigm (the coming of maturity of a
science) Pre-normal science there exists a range
of different schools, not united by a common
paradigm Normal science An attempt to force
nature into the preformed and rigid box that the
paradigm provides. The aim is to stay within the
Kuhn Normal science is puzzle solving. If the
puzzle is not solved, the failure reflects on the
scientist not on the paradigm. The person who
blames the paradigm will be seen as the carpenter
who blames his tools. The man who succeeds
proves himself an expert puzzle solver, and the
challenge of the puzzle is what drives him
on. Contrast Popper experiments test theories
not people (What do scientists actually do?
Donovan, Laudan and Laudan, 1992)
Kuhn A common paradigm frees the scientific
community from having to constantly re-examine
first principles community is free to
concentrate exclusively on the subtlest and most
esoteric of phenomena that concern it To turn
Sir Karls view on its head, it is precisely the
abandonment of critical discourse that marks the
transition to a science
Popper The normal scientist, as described by
Kuhn, has been badly taught. He has been taught
in a dogmatic spirit he is a victim of
indoctrination. He has learned a technique which
can be applied without asking for the reason why
as a consequence, he has become what may be
called an applied scientist, in contradistinction
to what I should call a pure scientist. He is
merely content to solve puzzles. I admit that
this kind of attitude exists But I can only say
that I see a very great danger in it and the
possibility of its becoming normal a danger to
science and, indeed, to our civilisation.
Kuhn Failure with a new problem is disappointing
but not surprising problems do not often yield
to the first attack. Scientists do not renounce
the paradigm. Difficult anomalies can be set
aside for future work. (It is OK to provisionally
ignore an apparent falsification of your
favourite theory!) The scientist who pauses to
examine every anomaly he notes will seldom get
significant work done.
Are anomalies simply ignored by scientists?
Dunbar 1997 Spent a year in four highly
productive molecular biology labs Anomalies,
especially those challenging core assumptions,
were especially closely attended to and used to
generate new hypotheses In 19th century,
Mercurys orbit was not fully explained by
Newtons theory. A scientist at the time says
that no planet had extracted more pain and
trouble and awarded astronomers with so much
anxiety How do psychologists respond to
Kuhn Crisis build up of anomalies that resist
solution. Creates a growing sense that the
paradigm has ceased to function adequately in the
exploration of nature.
Kuhn Crisis build up of anomalies that resist
solution. Creates a growing sense that the
paradigm has ceased to function adequately in the
exploration of nature. Having achieved the
status of a paradigm, a scientific theory is
declared invalid only if an alternative candidate
is available to take its place. The
methodological stereotype of falsification by
direct comparison with nature does not exist in
actual science The decision to reject one
paradigm is always simultaneously the decision to
accept another a comparison between paradigms
occurs. (Do scientist only treat difficulties as
acute if there is a rival? See Donovan et al)
Incommensurability between paradigms Kuhn There
is a sense in which work in different paradigms
cannot be compared (or are difficult to
compare). 1. Disagreement over the list of
problems to be solved. What causes conscious
awareness? How fast can mental images be
rotated? were not legitimate problems for
behaviourists. Information processing psychology
de-emphasized learning connectionism brought it
back to the fore
2. Disagreement over how to describe basic
observations A hypnotherapist might literally
see a subject going into trance, while an
academic researcher might just see someone
relaxing. Sam is an extrovert means different
things depending on your theory of extroversion
and how the extroversion scale was developed
The actual data are different when seen through
the lense of different paradigms. Must they
necessarily be? Same theory of telescope could
be used for providing data to test big bang and
steady state cosmology paradigms Same data on
childrens reading errors can be used for testing
connectionist and information processing
accounts of reading
Kuhn When two scientific schools disagree about
what are the problems what counts as a solution
what the data actually are they will talk past
each other in debating their respective
paradigms. So how can one choose between
different paradigms?
Kuhn Paradigm choice can never be settled by
logic and experiment alone. It is an act of
faith Despite all the problems a new paradigm
currently has, is it a way of practicing science
that is likely to be fruitful in providing
solutions to the puzzles it defines? In
paradigm choice there is no standard higher than
the assent of the relevant community.
Relativism Different theories are equally true,
its all relative to what a group believes In
paradigm choice there is no standard higher than
the assent of the relevant community. So the
community could not be mistaken? Does truth lie
in power? Does truth change when the community
changes its mind?
Need to distinguish Description of world from
world In order that one could be wrong. The
fact and the representation of a fact can be
different! (If you partner says I did/did not
sleep with your best friend Is either answer
just as true?) Yet Kuhn says when paradigms
change scientists literally live in a different
Kuhn inspired (with regret) a domination of
relativism in the humanities and social sciences
(e.g. post-modernism, science studies, social
constructionism) Consider this quote from
training material for teachers For many
centuries it was considered to be a fact that the
Sun revolves around the Earth. The appearance of
another theory, such as the diurnal rotation of
the earth, entailed the replacement of the fact
just cited with another the Earth rotates on its
axis each day. If facts change when we change
what we think, does it matter who we convict for
a rape? Can you jump from a plane and fly if you
believe you can?
Kuhn To go between paradigms, cannot be done
step by step it happens all at once like a
Gestalt switch. The transfer of allegiance from
paradigm to paradigm is a conversion experience.
Converting people is difficult. Typically new
paradigms are introduced by a person new to the
field. Max Planck A new scientific truth does
not triumph by convincing its opponents and
making them see the light, but rather because its
opponents eventually die, and a new generation
grows up that is familiar with it. Is that
Diamond 1992 Tiny non-significant correlations
between actual or professional age of 100
chemists and whether or not they supported the
radical theory of polywater Physicists of all
ages came to adopt quantum theory and relativity
rather than Newtonian dynamics as closer to the
truth in a very short period of time.
Kuhn Revolution the change of a paradigm in a
discipline Revolution is a transformation of
vision, crises are terminated not be deliberation
but by a gestalt switch. After a revolution the
data themselves change and the scientists work in
a different world.
Gestalt switch the data changes (Implications On
e way of looking at the data is not more true
than another ? One cannot simultaneously consider
the data from the point of view of two different
theories ?)
Are there objective reasons for why scientists
should favour one theory over another? Does
science tend to move closer to the truth? Do
scientists try to falsify fundamental theories?