How does use of the word theory differ

In common parlance, theory is often used to refer to something that is rather speculative. This definition strongly contrasts with the definition of theory as it is used in science: a theory is a carefully thought-out explanation for observations of the natural world that has been constructed using the scientific method, and which brings together many facts and hypotheses.

The term hypothesis is good to define in this discussion as well: a hypothesis is an idea that we can test with further scientific observations.

With these definitions in mind, a simplified version of the scientific process would be as follows. A scientist makes an observation of a natural phenomenon.

If the test falsifies the hypothesis i. If the hypothesis is corroborated i. If it survives additional scrutiny, she may eventually try to incorporate it into a larger theory that helps to explain her observed phenomenon and relate it to other phenomena. That's all fairly abstract, so let's look at a concrete example involving some recent research I undertook with a group of collaborators.

The theory of evolution states that the process of natural selection should work to optimize the function of an organism's parts if the changes increase the chances of the organism successfully producing offspring and the changes are heritable i. Consider a turtle's shell. Turtles with stronger shells will be more likely to survive encounters with predators, and thus will be more likely to successfully produce offspring.

Theories will pull together experimental results to provide full explanations such as "The Big Bang Theory. As anyone who has worked in a laboratory or out in the field can tell you, science is about process: that of observing, making inferences about those observations, and then performing tests to see if the truth value of those inferences holds up.

The scientific method is designed to be a rigorous procedure for acquiring knowledge about the world around us. In scientific reasoning, a hypothesis is constructed before any applicable research has been done. A theory, on the other hand, is supported by evidence: it's a principle formed as an attempt to explain things that have already been substantiated by data.

Toward that end, science employs a particular vocabulary for describing how ideas are proposed, tested, and supported or disproven. And that's where we see the difference between a hypothesis and a theory. A hypothesis is an assumption, something proposed for the sake of argument so that it can be tested to see if it might be true.

In the scientific method, the hypothesis is constructed before any applicable research has been done, apart from a basic background review. You ask a question, read up on what has been studied before, and then form a hypothesis. A hypothesis is usually tentative, an assumption or suggestion made strictly for the objective of being tested. When a character which has been lost in a breed, reappears after a great number of generations, the most probable hypothesis is, not that the offspring suddenly takes after an ancestor some hundred generations distant, but that in each successive generation there has been a tendency to reproduce the character in question, which at last, under unknown favourable conditions, gains an ascendancy.

Charles Darwin, On the Origin of Species , According to one widely reported hypothesis , cell-phone transmissions were disrupting the bees' navigational abilities. Few experts took the cell-phone conjecture seriously; as one scientist said to me, "If that were the case, Dave Hackenberg's hives would have been dead a long time ago.

A theory , in contrast, is a principle that has been formed as an attempt to explain things that have already been substantiated by data. It is used in the names of a number of principles accepted in the scientific community, such as the Big Bang Theory. Because of the rigors of experimentation and control, its likelihood as truth is much higher than that of a hypothesis.

It is evident, on our theory , that coasts merely fringed by reefs cannot have subsided to any perceptible amount; and therefore they must, since the growth of their corals, either have remained stationary or have been upheaved. Now, it is remarkable how generally it can be shown, by the presence of upraised organic remains, that the fringed islands have been elevated: and so far, this is indirect evidence in favour of our theory.

Charles Darwin, The Voyage of the Beagle , It is contrarianism True skepticism is, as [Carl] Sagan described it, the 'self-correcting machinery' of science," Mann said. The phrase " nature versus nurture " also gives scientists a headache, because it radically simplifies a very complicated process, said Dan Kruger, an evolutionary biologist at the University of Michigan. Genes may influence human beings, but so, too, do epigenetic changes. These modifications alter which genes get turned on, and are both heritable and easily influenced by the environment.

The environment that shapes human behavior can be anything from the chemicals a fetus is exposed to in the womb to the block a person grew up on to the type of food they ate as a child, Kruger said.

All these factors interact in a messy, unpredictable way. Does it mean statistically significant, or does it mean important? In statistics, something is significant if a difference is unlikely to be due to random chance. But that may not translate into a meaningful difference, in, say, headache symptoms or IQ. The term has become synonymous with being virtuous, healthy or good.

But not everything artificial is unhealthy, and not everything that's natural is good for you. Natural's sibling "organic" also has a problematic meaning, he said. While organic simply means "carbon-based" to scientists, the term is now used to describe pesticide-free peaches and high-end cotton sheets, as well.

But though these words may be routinely misunderstood, the real problem, scientists say, is that people don't get rigorous science education in middle school and high school. As a result, the public doesn't understand how scientific explanations are formed , tested and accepted.

What's more, the human brain may not have evolved to intuitively understand key scientific concepts such as hypotheses or theories, Kruger said. Most people tend to use mental shortcuts to make sense of the cacophony of information they're presented with every day.

One of those tendencies is to make a "binary distinction between something that is true in an absolute sense and something that's false or a lie," Kruger said. We're continually building our understanding. All rights reserved.