Copperbrain.png
Scientific method

From RationalWiki

Jump to: navigation, search
Part of the series on
Philosophy of
science
Compound Microscope 1876.JPG
Foundations
Method
Conclusions
Once upon a time, there was a man who was convinced that he possessed a Great Idea. Indeed, as the man thought upon the Great Idea more and more, he realized that it was not just a great idea, but the most wonderful idea ever. The Great Idea would unravel the mysteries of the universe, supersede the authority of the corrupt and error-ridden Establishment, confer nigh-magical powers upon its wielders, feed the hungry, heal the sick, make the whole world a better place, etc. etc. etc.

The man was Francis Bacon, his Great Idea was the scientific method, and he was the only crackpot in all history to claim that level of benefit to humanity and turn out to be completely right.

—Eliezer Yudkowsky[1]

The scientific method is an epistemological system for deriving and developing knowledge. It is considered the best method for making useful and practical additions to human knowledge, and has resulted in the technological leaps made since it developed in the western world.[2] At the core of the method is the idea that the truth value of a hypothesis, theory, or concept is best determined by its ability to make falsifiable predictions that can be tested against an empirical reality. This is in contrast with other schools of thought that do not suppose that truth can be tested, and can merely be asserted or derived with sufficient "thought" or other ways of knowing.

The scientific method means that supernatural entities or concepts that are attached to woo and bullshit cannot be included in a scientific hypothesis (not least because you can't put a sample of a god in a test-tube). Consequently, when carrying out investigations scientists assume a position of methodological naturalism.

Humans, including scientists, are fallible and irrational apes by nature. The scientific method, therefore, helps these highly imperfect beings iron out their biases and develop good and useful results.

Contents

[edit] How to do science

Creationists probably wouldn't come away with any points.

The scientific method isn't a simple, linear process, but is wrapped up in the complexities of research in the real world and the practicalities of what is possible. However, the idea of testing a hypothesis and refining knowledge based on observation is a constant theme of science.[3]

Despite the lack of simple linearity in reality, the method has often been codified into stages that make it easier to understand. Essentially, the following five steps make up the scientific method:

  1. Observe - look at the world and find a result that seems curious.
  2. Hypothesize - come up with a reasonable explanation.
  3. Predict - the most important part of a hypothesis or theory is its ability to make predictions. These predictions should be falsifiable and specific.
  4. Experiment - compare the predictions with empirical evidence (usually experimental evidence, often supported by mathematics). This step is the reason why a hypothesis or theory has to be falsifiable, if you can't prove it wrong, you can't really prove it right. Information from these predictions can lead to a refinement of the hypothesis.
  5. Reproduce - ensure the result is a true reflection of reality by verifying it with others.

The testing of hypotheses allows for error correction and the development of better models. One of the notable examples is the development of atomic theory - the theory that describes what atoms "look like". From the "plum pudding" model, to the Rutherford Model, and then to the Bohr Model and modern quantum physics, the atom developed in steps because each model made predictive statements that could be tested. Thus the theory is refined over time and as observational evidence increases in support of it. That evidence supports a hypothesis implies that the hypothesis is stronger (and more likely to be valid) than before the test. On the other hand, evidence against a hypothesis makes it invalid, thus falsifying it.[4] It is an inductive method, although its results can be used deductively as well.

All but the first two steps are omitted from the process in pseudosciences such as intelligent design (where step 3 would be impossible) and most borderline-supernatural alternative medicines like homeopathy. Pseudosciences do observe the world, and do come up with explanations, but are often unable or unwilling to follow through in testing them more thoroughly. Refining the hypotheses is also undesirable in pseudoscience as this could lead to abandoning the central dogma of the belief - imagine where modern technology would be if the scientists of the 20th century refused to modify the structure of the atom as new observational evidence came in? However, because observations and explanations still form a part of pseudoscience and can be phrased in a scientific style, pseudosciences may mistakenly appear to have scientific authority.

Galileo Galilei and Francis Bacon were among the first scientists to use the scientific method in the modern, western world, taking over from the Greek method that prioritised rational thought over empiricism. Prior to this, the scientific method was used widely in the "Islamic Golden Age", a time between the 7th and 12th Centuries and Arabic Science even generated a system of peer review. Arabic science went into a steady decline as the Islamic world became dominated by orthodox and fundamentalist theology. The scientific method was not always accepted during its period of development and the work of Ignaz Semmelweis provides a telling example of what happens when the method, or the conclusions arrived at by its use, are ignored.

[edit] Skepticism

Scientific skepticism is a vital element in the scientific process, ensuring that no new hypothesis is considered a Theory (capped T) until sufficient evidence is provided and other scientists have had their chances to debunk it. Even then, all of science is always considered a "good working model" and the "best understanding we have at the present time". No scientific idea is ever considered "the final word" (like you would see in a dogmatic setting like religion). It is always assumed that someone, somewhere is out to disprove the current theory, thus pushing the science skepticism.

[edit] Philosophical perspectives

Science is far from the perfect instrument of knowledge. It's just the best we have.

—Carl Sagan. The Demon-Haunted World, Science as a Candle in the Dark

Philosophy of science dates back to the Greeks, but its modern form is seen in the works of Karl Popper and Thomas Kuhn. Popper described the modern formulation of falsifiability, that is, for an idea to be "scientific" it must be possible to devise an experiment (even a thought experiment) that could render it false. Kuhn described the dynamics of scientific change, coining the terms scientific revolution and paradigm shift to help described what he saw as the way a fundamentally conservative set of ideas could be overturned and become a new, different set of conservative ideas. Summary: humans remain humans and don't naturally think in a scientific manner, but have to learn it, and easily backslide.

There are other schools of "scientific criticism" that look at science critically from an economic perspective, or that focus on discourse, but these are more academic and less practical critiques.

[edit] The problem of solipsism

Solipsism proposes that the only thing we can be sure of - i.e., the only thing that can be conclusively proven without any prior assumptions - is that we experience therefore we exist, in some form at least. The scientific method requires certain a priori assumptions of epistemology and metaphysics in order to even get out of the starting gate. It assumes you are not a brain in a vat and that Last Thursdayism does not apply. If you are trapped in some sort of Descartian nightmare of being certain of your own "existence" and rejecting everything else then there is nothing for science to do.

In order to demonstrate that the scientific method is the single best source for knowledge, two major axioms have to be set. The first is that "some ideas are more wrong than others," and the second is that "our sensory experiences correlate with some sort of external reality". Specifically, the scientific method assumes these axioms because there is no reason or evidence available via the scientific method to say otherwise. This is slightly circular but it does lead to science being internally consistent. If you agree to those first assumptions regarding the nature of reality, the scientific methods falls out pretty quickly as the path to knowledge.

[edit] Cheating the scientific method

Science and faith are highly conflicting methods for learning about the world.

Pseudoscientists have discovered an obvious way to 'cheat' the scientific method.
It goes like this:

  1. Pick a personal belief that you want to 'prove' is true.
  2. Make new observations or experiments, and note the results.
  3. Think up some clever way by which to shoehorn your personal belief to said results.
  4. Falsely claim that your personal belief predicts the particular results, and that the observations/experiment confirmed your suspicions.

This manner of cheating has been used by proponents of intelligent design.

Note that this isn't limited to pseudoscientists such as those trying to grant legitimacy to intelligent design, but is a mistake frequently made even by "proper" scientists, if they focus too much on finding evidence that supports their hypothesis (their "belief"), instead of focusing on attempting to find evidence that would refute it, or on attempting to find evidence that would refute competing hypotheses.

[edit] See also

[edit] Footnotes

  1. Resist the Happy Death Spiral
  2. It was also developed elsewhere, such as in the Islamic Golden Age, around 8th to the 13th Centuries in the Middle East - where Jābir ibn Hayyān developed experimental methods for chemistry.
  3. Robinson, W. R. "The Inquiry Wheel, An Alternative to the Scientific Method." J. Chem. Ed. 2004(81): 791-2.
  4. That the scientific method works this way is implied by Bayesian mathematics.
Personal tools
Namespaces
Variants
Actions
Navigation
Community
Toolbox
In other languages
support