Is the Replicability of Experiment a Principle of Inductive Logic? John D. Norton Department of History and Philosophy of Science Center for Philosophy of Science University of Pittsburgh

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Is the Replicability of Experiment a Principle
ofInductive Logic? John D. NortonDepartment
of History and Philosophy of ScienceCenter for
Philosophy of ScienceUniversity of Pittsburgh

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NO.
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This Talk

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Why Ask?(if it is a principle)
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What Powers Inductive Inference?Which are the
Good Inductive Inferences?
Formal Accounts. Modeled on deductive
inference.Inferences warranted by conformity to
universal schema, principles.
Material account. Inductive inferences by
facts. There are no universal schema. All
induction is local.
vs

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Which formal schema, principles work in a formal
theory?
Enumerative Induction
Hypothetico-Deductive Confirmation
Inference to the Best Explanation
Bayesian Probability

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Replication is the gold standard
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The Reproducibility of an experimental result
is a fundamental assumption in science.
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Journal of Irreproducible Results

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(No Transcript)
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RepeatablevsReproducible
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Repeatability vs Reproducibility
Reproducibility requires that the same
measurement must reappear under changed
conditions.
Repeatability requires that the same
measurements must reappear under the same
conditions.
Replicability
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The Formal Approach
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A Principle of Replicability?
Successful replication of an experiment is a good
indicator of a veridical experimental
outcome failure of replication is a good
indicator of a spurious experimental outcome.

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Problems
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Not self-contained
What is a process or effect sought by the
experimental design
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Case Studies
Import of replicability discarded
Import of replicability upheld (mostly)
Succesful replication
H. Pylori and Stomach Ulcers (result accepted as
veridical)
Intercessionary prayer (result rejected as
spurious)
Failed replication
Cold fusion (result rejected as spurious and
skeptics discount cases of successful
replication)
Miller experiment contradicts relativity
theory (relativity theory upheld)
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Material Analysis
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The Facts that Warrant
Inferences concerning outcome of a single
experiment warranted by
Class A. Facts that show outcome can come from
process or effect sought.

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Replication in a Material Analysis
Inferences concerning outcome of a single
experiment warranted by
Class A. Facts that show outcome can come from
process or effect sought.
Class B. Facts that show outcome cannot come from
other processes.
Combine A B Outcome does come from process or
effect sought.

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Cases
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H. Pylori produce ulcers and gastritis
Rapid replication of experiments.
Barry Marshall and Robin Warren Nobel Prize 2005
for work in 1980s

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Dayton C. Millers failed 1925 replications of
the Michelson-Morley Experiment

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Dayton C. Millers failed 1925 replications of
the Michelson-Morley Experiment
I think that the Miller experiments rest on an
error in temperature. I have not taken them
seriously for a minute. To Michele Besso,
December 25, 1926

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Cold FusionMartin Fleischmann and B. Stanley
Pons, March 1989
Nuclear fusion reaction created by electrolysis
of heavy water in a jar on a laboratory bench.
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Cold Fusion Skeptics
The initial announcement by Pons and
Fleischmann in March 1989 exhibited the
discrepancy between heat and fusion products in
sharp terms. Namely, the level of neutrons they
claimed to observe was 109 times less than that
required if their stated heat output were due to
fusion.
cold fusion should not be possible based on
established theory.
ERAB, Report.
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Cold Fusion Proponents
If theory and observation are in conflict,
theory wins in the skeptics view.
reality-based science acknowledges what nature
reveals and then attempts to find an explanation.
Rejection occurs only if a satisfactory
explanation cannot be demonstrated. This
demonstration is still in progress for cold
fusion.
Sturms, Edmund (2007), The Science of Low Energy
Nuclear Reaction A Comprehensive Compilation of
Evidence and Explanations about Cold Fusion.
Singapore World Scientific Publishing. (p. 13)

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Controlled Studies of Intercessionary Prayer
The sovereigns are literally the shortest lived
of all who have the advantage of affluence. The
prayer has therefore no efficacy, unless the very
questionable hypothesis be raised, that the
conditions of royal life may naturally be yet
more fatal, and that their influence is partly,
though incompletely, neutralized by the effects
of public prayers. Galton (1872)
19th century a tool of skeptics.
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A Catholic, a Protestant and a Jew, set out a
test of distant prayer.
became convinced that the very idea of testing
distant prayer scientifically was fundamentally
unsound.
The epistemology that governs prayer (and all
matters of faith) is separate from that which
governs nature. Why, then, attempt to explicate
it as if it were a controllable, natural
phenomenon?
Chibnall, John T. et al. (2001) Experiments on
Distant Intercessory Prayer God, Science, and
the Lesson of Massah, Archives of Internal
Medicine, 161, pp. 2529-36.
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Conclusion
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Superfluity of the Formal Analysis
Material analysis gives a transparent account of
the the diversity of inductive inferences
surrounding replication of experiment.
For the better, since we have not been able to
formulate one.
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The End