Like many words in common usage, “science” has come to mean different things. Its meaning also often depends on the context in which it is used. What are the distinguishing characteristics of science?
Basic science is a process, a way of objectively discovering the workings of nature. Applied science and engineering have somewhat different objectives, which are reflected in their methods.
The methods employed require a level of rigor sufficient to assure investigators don’t mislead themselves. However, in common usage, people refer to many things requiring rigor as scientific. Though they may have elements of rigor resembling those used in science, often they are missing important parts of the process, or have none of them.
Sometimes adherence to logical reasoning is equated with being scientific. Surely, science employs logical reasoning, but not all logical reasoning follows scientific methods.
What scientists do in preparation for engaging in the scientific process confuses things further. First, they formulate the questions they want answered. Questions are unlikely to be meaningful if they aren’t derived from an existing, comprehensive knowledge base.
Incompleteness in understanding is identified by comparing and contrasting bits of existing knowledge. This is followed by formulation of preliminary conjectures: “If this, maybe that,” “Could it be possible these things are related,” “I don’t have a clue about this, but it seems to have similarities to that.”
This is perhaps the more creative or insightful part of science. It is where curious minds start exploring possibilities.
Confusion arises when these conjectures are aired to audiences ill equipped to distinguish what are just seeds of an idea from the process that follows. Such audiences misunderstand that at this stage scientists aren’t claiming to know something but are only searching for a path to new knowledge.
Eventually, conjectures must mature into plausibility arguments. One begins asking, “Does this kernel of an idea violate any well-established principles and is it consistent within itself?”
In an earlier article I wrote about “gedanken,” or thought experiments. Scientists mentally test their ideas under a variety of scenarios for consistency with what is known.
This is followed by the more rigorous phase of the scientific method, formulating hypotheses: “This is what I think might be true.” It would be less confusing if hypotheses were not referred to as theories, but conflating these terms persists.
Hypotheses must be clearly stated and free of ambiguity. They must be falsifiable. If there is no possibility of their being disproven, they aren’t valid hypotheses.
Validation of hypotheses depends on the quality of supporting data. The means of acquiring data must be free of bias. One must be able to demonstrate that the methods and instruments used cannot skew the results.
Frequent mistakes are made in asserting that, since certain observations correlate with a given phenomenon, they must be its cause. For basic science, it isn’t satisfying to simply state an observation that a particular thing always happens following some set of events.
Proof of direct cause-effect relationships must demonstrate the mechanism of action of one thing on another. Furthermore, there can’t be other credible explanations for the data.
In addition to needing sufficient data to support experimenters’ inferences, uncertainties in the data and confidence levels in the inferences need to be identified and, where appropriate, quantitated.
Results must be published in peer reviewed journals and presented at conferences. Enough must be divulged to allow reviewers, the readership or conference attendees to question the integrity of the methods and validity of the conclusions.
At some point, researchers might formulate principles from their results when those principles explain a diversity of facts or phenomena. These are called theories, a term that should be reserved for unifying ideas which have been repeatedly tested and accepted and which are used to make predictions.
Unfortunately, colloquial usage gives rise to a second definition of completely different meaning: an assumption based on limited information or knowledge; a conjecture.This puts the cart before the horse and creates misunderstandings of the entire scientific method.
Applied research, though having many aspects of basic research, has different objectives. Applied researchers take knowledge generated by basic research to fabricate something new having unique and useful properties, or to invent new, beneficial processes.
Though the distinction between applied science and engineering can be fuzzy, usually engineers have very specific products in mind. Their task is to exploit the newly created materials or methods for practical applications.
Basic and applied researchers and engineers typically take the same introductory coursework in college: physics, chemistry, biology and mathematics. But, as their skills advance their studies diverge.
Their professional organizations have standards of performance. Those standards have science-like commonalities, but their fundamental objectives are different.
The distinctions I have drawn may seem unimportant, but I argue lack of clarity has frequently distorted the public’s perception of science.
Steve Luckstead is a medical physicist. He can be reached at firstname.lastname@example.org.