Reproducibility is the ability of an entire experiment or study to be reproduced, either by the researcher or by someone else working independently. It is one of the main principles of the scientific method. The result values are said to be commensurate if they are obtained (in distinct experimental trials) according to the same reproducible experimental description and procedure. The basic idea can be seen in Aristotle's dictum that there is no scientific knowledge of the individual, where the word used for individual in Greek had the connotation of the idiosyncratic, or wholly isolated occurrence. Thus all knowledge, all science, necessarily involves the formation of general concepts and the invocation of their corresponding symbols in language (cf. Turner).
Reproducibility also refers to the degree of agreement between measurements or observations conducted on replicate specimens in different locations by different people, as part of the precision of a test method.
Reproducible data 
Reproducibility is one component of the precision of a test method. The other component is repeatability which is the degree of agreement of tests or measurements on replicate specimens by the same observer in the same laboratory. Both repeatability and reproducibility are usually reported as a standard deviation. A reproducibility limit is the value below which the difference between two test results obtained under reproducibility conditions may be expected to occur with a probability of approximately 0.95 (95%).
Reproducible research 
The term reproducible research refers to the idea that the ultimate product of research is the paper along with the full computational environment used to produce the results in the paper such as the code, data, etc. necessary for reproduction of the results and building upon the research.
In 2012, a study found that 47 out of 53 medical research papers on the subject of cancer were irreproducible.
John P. A. Ioannidis wrote:
- While currently there is unilateral emphasis on "first" discoveries, there should be as much emphasis on replication of discoveries."
While repeatability of scientific experiments is desirable, it is not considered necessary to establish the scientific validity of a theory. For example, the cloning of animals is difficult to repeat, but has been reproduced by various teams working independently, and is a well established research domain. One failed cloning does not mean that the theory is wrong or unscientific. Repeatability is often low in protosciences.
Noteworthy irreproducible results 
Hideyo Noguchi became famous for correctly identifying the bacterial agent of syphilis, but also claimed that he could culture this agent in his laboratory. Nobody else has been able to produce this latter result.
In March 1989, University of Utah chemists Stanley Pons and Martin Fleischmann reported the production of excess heat that could only be explained by a nuclear process ("cold fusion"). The report was astounding given the simplicity of the equipment: it was essentially an electrolysis cell containing heavy water and a palladium cathode which rapidly absorbed the deuterium produced during electrolysis. The news media reported on the experiments widely, and it was a front-page item on many newspapers around the world (see science by press conference). Over the next several months others tried to replicate the experiment, but were unsuccessful.
Nikola Tesla claimed as early as 1899 to have used a high frequency current to light gas-filled lamps from over 25 miles (40 km) away without using wires. In 1904 he built Wardenclyffe Tower on Long Island to demonstrate means to send and receive power without connecting wires. The facility was never fully operational and was not completed due to economic problems.
See also 
- ASTM E177
- ASTM E177
- ASTM E691 Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
- ASTM F1469 Standard Guide for Conducting a Repeatability and Reproducibility Study on Test Equipment for Nondestructive Testing
- Sergey Fomel and Jon Claerbout, "Guest Editors' Introduction: Reproducible Research," Computing in Science and Engineering, vol. 11, no. 1, pp. 5–7, Jan./Feb. 2009, doi:10.1109/MCSE.2009.14
- J. B. Buckheit and D. L. Donoho, "WaveLab and Reproducible Research," Dept. of Statistics, Stanford University, Tech. Rep. 474, 1995.
- The Yale Law School Round Table on Data and Core Sharing: "Reproducible Research", Computing in Science and Engineering, vol. 12, no. 5, pp. 8–12, Sept/Oct 2010, doi:10.1109/MCSE.2010.113
- Is the spirit of Piltdown man alive and well?
- Cheney, Margaret(1999), Tesla Master of Lightning, New York: Barnes & Noble Books, ISBN 0-7607-1005-8, pp. 107.; "Unable to overcome his financial burdens, he was forced to close the laboratory in 1905."
- Turner, William (1903), History of Philosophy, Ginn and Company, Boston, MA, Etext. See especially: "Aristotle".
- Definition (PDF),[dead link] by International Union of Pure and Applied Chemistry
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