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Scientific Laws and Theories

Scientific Laws and Theories teaches students about the differences between a law and a theory when it comes to science. Students will also learn how to differentiate among facts, beliefs, and hypotheses. They will be able to give examples of each of these five concepts.

There are additional suggestions in the “Options for Lesson” section of the classroom procedure page that you could incorporate into the lesson plan. For example, one idea is to divide students into five groups and assign each group one of the five concepts from the lesson to research further.

Description

Additional information, what our scientific laws and theories lesson plan includes.

Lesson Objectives and Overview: Scientific Laws and Theories introduces students to difference between a law and a theory in relation to the field of science. Students will discover what a fact is, what a hypothesis is, and what a belief is. They will learn how to differentiate among these five concepts and give examples of each. This lesson is for students in 5th grade and 6th grade.

Classroom Procedure

Every lesson plan provides you with a classroom procedure page that outlines a step-by-step guide to follow. You do not have to follow the guide exactly. The guide helps you organize the lesson and details when to hand out worksheets. It also lists information in the yellow box that you might find useful. You will find the lesson objectives, state standards, and number of class sessions the lesson should take to complete in this area. In addition, it describes the supplies you will need as well as what and how you need to prepare beforehand.

Options for Lesson

You can check out the “Options for Lesson” section of the classroom procedure page for additional suggestions for ideas and activities to incorporate into the lesson. For the activity, students could work alone or in groups instead of in pairs. In addition, you could add a second or third scenario. Another option is to haves students create posters that show the differences among each of the scientific terms. You could also divide students into five groups, assign each group a term, and have the students research it further and find more examples. Another suggestion is to invite a scientist to the class to speak with students and answer their questions. One more options is to use current science content and have students identify facts, beliefs, theories, hypotheses, and laws from the content.

Teacher Notes

The teacher notes page provides an extra paragraph of information to help guide the lesson. It suggests teaching this lesson in conjunction with others that relate to the scientific method, processing skills, and so on. You can use the blank lines to write down any other ideas or thoughts you have about the topic as you prepare.

SCIENTIFIC LAWS AND THEORIES LESSON PLAN CONTENT PAGES

Laws, theories, facts, and more.

The Scientific Laws and Theories lesson plan contains four pages of content. Science concepts can often be quite simple or extremely difficult to understand. Students have probably learned many science-related concepts and ideas, such as the three main states of matter. They might understand that there are three states and be able to identify examples of each. But they may not understand why some matter can turn into a solid or why other substances can never turn into a liquid or gas.

There are a lot of scientific concepts, and we can’t label them all the same way. Scientists label their ideas as facts, theories, hypotheses, laws, or beliefs, depending on the traits or qualities of the idea. All these terms carry a different meaning in the field of science, and all scientists need to understand them.

Facts, Laws, and Hypotheses

The lesson provides a chart that explains each of the five labels. First, students will learn what a fact is in the field of science. Facts are basic statements that scientists have proven to be true through experiments and observation. If we observe rain from the sky, it is a fact that it’s raining. All facts are true under specific conditions, but in science, they may later be proven false when retested using better instruments or more thorough observation.

A law is a logical relationship between two or more things based on a variety of facts and proven hypotheses. Laws are often shown using mathematical formulas or statements of how two or more quantities relate to each other. Newton’s law of gravity, for example, predicts the behavior of a dropped object but does not explain why the object drops.

In science class, students often start an experiment with a hypothesis, an educated guess about what will happen and what they might observe. A hypothesis is a prediction of cause and effect. Additional experimentation and observation will either support or disprove a hypothesis. For instance, we might guess that all cleaning products are the same. After testing this idea out, we learn that some products are actually better than others, proving our hypothesis false.

Theories and Beliefs

A theory is the “why” in science. Theories explain why certain laws and facts exist, and we can test theories to determine their accuracy. Repeated testing can support a theory, and that theory will remain valid if there is no evidence to dispute it. Many times, we can label a theory as an accepted hypothesis.

One example of a theory is the idea that a large crater on Earth might have been caused by a meteor strike. However, this idea is not a proven fact, but many accept it to be true based on collected evidence. On the other hand, it’s possible that we can disprove the theory and find it to be false.

Finally, students will learn about beliefs. In science, a belief is a statement that is not scientifically provable in the same way as facts, laws, hypotheses, and theories. Beliefs that we proved to be false today can later be proven true by someone else using scientific experimenting and observation.

An example of a belief is the scenario in which many people believe there are certain lucky numbers, and the position of the planets affect how people behave. However, we cannot prove either of these beliefs to be true. It’s still possible that someone someday could change either of these beliefs into a fact after experimenting and observing.

Understanding the Difference

The difference between a theory, a law, a fact, and a hypothesis is subtle. Theories, laws, and facts often start out as as hypothesis when someone originally proposes it. After going through rigorous testing, experimentation, and observation, it’s possible that the hypothesis becomes one of the other three.

In addition, a fact may be true with certain conditions. For example, water boils at 212 °F at sea level, but at higher altitudes, it boils at lower temperatures. Every fact will depend on the specific circumstances under which a measurement is made. It is important to understand the differences.

How can you tell if a statement is a fact, law, hypothesis, theory, or belief? Facts are the statements that everyone knows to be true through direct observation. In science, we base facts on many lines of evidence. For example, at one time, it was a hypothesis that the planets circled the sun. With more observation and experimentation over time (and with better instruments), we learned that this was true, a fact. Newton discovered the law of gravity but could not explain why it worked. But others have explained it with a theory as to why it works. A theory will not become a law but explains the law.

The bottom of this page provides examples of each of the five categories of scientific concepts. Water freezes at 32°F, matter comprises atoms, and black holes exist. These are all facts. For every action, there is an equal and opposite reaction. Energy equals mass times the speed of light squared. Energy cannot be created or destroyed in a chemical reaction. These are all laws.

In the hypothesis group are three more statements. The sun will rise tomorrow morning. The universe was created at the big bang. Eating more vegetables will help a person lose weight. Theories include the idea that plate tectonics explain the movement of the continents. Natural selection explains the concept of evolution. Microorganisms cause many diseases.

Finally, humans were created separately from all other life on Earth. There are no such things as ghosts. The number 13 is unlucky, but the number 7 is lucky. These three statements all fall into the beliefs category.

SCIENTIFIC LAWS AND THEORIES LESSON PLAN WORKSHEETS

The Scientific Laws and Theories lesson plan includes three worksheets: an activity worksheet, a practice worksheet, and a homework assignment. Each one will reinforce students’ comprehension of lesson material in different ways and help them demonstrate when they learned. Use the guidelines on the classroom procedure page to determine when to distribute each worksheet to the class.

IMAGINATION ACTIVITY WORKSHEET

Students will work with a partner for the activity. The worksheet provides five separate prompts regarding different scenarios about astronauts visiting a new planet. Students will collaborate and share their ideas and thoughts with each other as they develop the answers for the prompts. The five prompts relate to either a hypothesis, fact, law, theory, or belief.

SCIENTIFIC LAWS AND THEORIES PRACTICE WORKSHEET

The practice worksheet divides into two sections. On the first section, students will match 15 explanations to the correct term. There is a word bank with five terms to choose from. Students will use each one three times. The second section requires students to decide whether each of five statements is true (T) or false (F).

FACT, THEORY, HYPOTHESIS, LAW, OR BELIEF HOMEWORK ASSIGNMENT

For the homework assignment, students will look at 20 statements. They must decide if the statement represents a fact (F), theory (T), hypothesis (H), law (L), or belief (B). The worksheet mentions that they can use the internet or other resources for help if necessary.

Worksheet Answer Keys

At the end of the lesson plan document are answer keys for the practice and homework worksheets. The correct answers are in red to make it easy to compare them to studnets’ work. If you choose to administer the lesson pages to your students via PDF, you will need to save a new file that omits these pages. Otherwise, you can simply print out the applicable pages and keep these as reference for yourself when grading assignments.

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Hypothesis vs. Theory

A hypothesis is either a suggested explanation for an observable phenomenon, or a reasoned prediction of a possible causal correlation among multiple phenomena. In science , a theory is a tested, well-substantiated, unifying explanation for a set of verified, proven factors. A theory is always backed by evidence; a hypothesis is only a suggested possible outcome, and is testable and falsifiable.

Comparison chart

Examples of Theory and Hypothesis

Theory: Einstein's theory of relativity is a theory because it has been tested and verified innumerable times, with results consistently verifying Einstein's conclusion. However, simply because Einstein's conclusion has become a theory does not mean testing of this theory has stopped; all science is ongoing. See also the Big Bang theory , germ theory , and climate change .

Hypothesis: One might think that a prisoner who learns a work skill while in prison will be less likely to commit a crime when released. This is a hypothesis, an "educated guess." The scientific method can be used to test this hypothesis, to either prove it is false or prove that it warrants further study. (Note: Simply because a hypothesis is not found to be false does not mean it is true all or even most of the time. If it is consistently true after considerable time and research, it may be on its way to becoming a theory.)

This video further explains the difference between a theory and a hypothesis:

Common Misconception

People often tend to say "theory" when what they're actually talking about is a hypothesis. For instance, "Migraines are caused by drinking coffee after 2 p.m. — well, it's just a theory, not a rule."

This is actually a logically reasoned proposal based on an observation — say 2 instances of drinking coffee after 2 p.m. caused a migraine — but even if this were true, the migraine could have actually been caused by some other factors.

Because this observation is merely a reasoned possibility, it is testable and can be falsified — which makes it a hypothesis, not a theory.

• What is a Scientific Hypothesis? - LiveScience
• Wikipedia:Scientific theory

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Comments: Hypothesis vs Theory

Anonymous comments (2).

October 11, 2013, 1:11pm "In science, a theory is a well-substantiated, unifying explanation for a set of verified, proven hypotheses." But there's no such thing as "proven hypotheses". Hypotheses can be tested/falsified, they can't be "proven". That's just not how science works. Logical deductions based on axioms can be proven, but not scientific hypotheses. On top of that I find it somewhat strange to claim that a theory doesn't have to be testable, if it's built up from hypotheses, which DO have to be testable... — 80.✗.✗.139

May 6, 2014, 11:45pm "Evolution is a theory, not a fact, regarding the origin of living things." this statement is poorly formed because it implies that a thing is a theory until it gets proven and then it is somehow promoted to fact. this is just a misunderstanding of what the words mean, and of how science progresses generally. to say that a theory is inherently dubious because "it isn't a fact" is pretty much a meaningless statement. no expression which qualified as a mere fact could do a very good job of explaining the complicated process by which species have arisen on Earth over the last billion years. in fact, if you claimed that you could come up with such a single fact, now THAT would be dubious! everything we observe in nature supports the theory of evolution, and nothing we observe contradicts it. when you can say this about a theory, it's a pretty fair bet that the theory is correct. — 71.✗.✗.151

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• Key Differences

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Difference Between Hypothesis and Theory

The term ‘hypothesis’ is often contrasted with the term theory which implies an idea, typically proven, which aims at explaining facts and events. Both hypothesis and theory are important components of developing an approach, but these are not same. There exist a fine line of difference between hypothesis and theory, discussed in this article, have a look.

Content: Hypothesis Vs Theory

Comparison chart.

Definition of Hypothesis

An unproven statement or a mere assumption to be proved or disproved, about a factor, on which the researcher is interested, is called a hypothesis. It is a tentative statement, which is concerned with the relationship between two or more phenomena, as specified by the theoretical framework. The hypothesis has to go through a test, to determine its validity.

In other words, the hypothesis is a predictive statement, which can be objectively verified and tested through scientific methods, and relates the independent factor to the dependent one. To a researcher, a hypothesis is more like a question which he intends to resolve. The salient features of hypothesis are:

• It must be clear and precise or else the reliability of the inferences drawn will be questioned.
• It can be put to the test.
• If the hypothesis is relational, it should state the relationship between independent and dependent variables.
• The hypothesis should be open and responsive to testing within the stipulated time.
• It should be limited in scope and must be clearly defined.

Definition of Theory

An idea or a broad range of ideas that are assumed to be true, which aims at explaining cause and effect relationship between multiple observed phenomena. It is based on hypothesis, which after a thorough analysis and continuous testing and confirmation through observation and experiments, becomes a theory. As it is backed by evidence, it is scientifically proven.

Just like hypothesis, theories can also be accepted or rejected. As more and more information is gathered on the subject, theories are modified accordingly, to increase the accuracy of prediction over time.

Key Differences Between Hypothesis and Theory

The points given below are vital, so far as the difference between hypothesis and theory is concerned:

• Hypothesis refers to a supposition, based on few pieces of evidence, as an inception of further research or investigation. A theory is a well-affirmed explanation of natural phenomena, which is frequently validated through experimentation and observation.
• While the hypothesis is based on a little amount of data, the theory is based on a wide set of data.
• The hypothesis is an unproven statement; that can be tested. On the other hand, the theory is a scientifically tested and proven explanation of fact or event.
• Hypothesis relies on suggestions, prediction, possibility or projects whereas a theory is supported by evidence and is verified.
• The hypothesis may or may not be proved true, so the result is uncertain. On the contrary, the theory is one, that is assumed to be true and so its result is certain.
• Hypothesis and theory are two levels of the scientific method, i.e. theory follows hypothesis and the basis for research is hypothesis whose outcome is a theory.

Both hypothesis and theory are testable and falsifiable. When a hypothesis is proved true, by passing all critical tests and analysis, it becomes a theory. So, the hypothesis is very different from theory, as the former is something unproven but the latter is a proven and tested statement.

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BELLENS MOTEBEJANE says

July 15, 2019 at 2:31 pm

AMAIZING !WHAT ARE THE DIFFERENCE BETWEEN THEORY AND LAW?

February 17, 2022 at 3:47 am

Thanks, I’m finally clear on this for the first time in my life of 65 years

Curtis Le Gendre says

September 14, 2022 at 8:02 am

Great Information

Kenneth says

November 19, 2022 at 2:10 am

I was looking for some takes on this topic, and I found your article quite informative. It has given me a fresh perspective on the topic tackled. Thanks!

Stefanie Banis says

February 9, 2024 at 6:35 pm

Very informative! Thank you! I understand the difference much better now!

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Hypotheses, Theories and Laws

Cite this chapter.

• Peter Pruzan 2  

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Although we tend to speak of hypotheses, theories, and laws as though they were clearly differentiated, this is not the case; the distinctions are not clear and are primarily a matter of belief regarding how well relationships that have been conjectured are supported by evidence. But scientific theories and laws are far more than just matters of faith; they are also the product of a methodology that has developed via continual confrontation with reality. It is not an exaggeration to state that scientific theories and laws are the most reliable forms of generalization produced by rational human activity. Faith and rationality can co-exist in science in a most vital symbiosis!

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We will see later on when the focus is on the test of hypotheses that this is the so-called “alternative hypothesis”, the hypothesis we are interested in and that motivates the study. The “null hypothesis” here would be that the behaviour of the dogs and monkeys in the ashram is not different from dogs and monkeys who do not frequent the ashram.

It should be noted here that Einstein did not just formulate his theory (which, in fact was a hypothesis that later became accepted as a theory) on the basis of intuition; his formulation of relativity theory was preceded by the Michelson-Morley experiment on the velocity of light.

The term “model”, which we have met several times until now, is often used interchangeably with “theory”, although it most often refers to a representation of a theory. In the case of many of the natural sciences, this representation is most often in the form of a mathematical model, i.e. a system of equations representing the interrelationships between variables. The term “model” often refers as well to physical or pictorial representations. Examples could be a physical structure representing a geocentric model of the universe or a visual model created on a computer (and generated by a mathematical model) of the double helix of DNA with its two polynucleotide strands woven around each other and running in opposite directions.

Having just considered an example involving fossils, I am tempted to mention that what is considered by many to be one of, if not the most successful and fundamental theories in the biosciences, that of evolution, is regarded by a number of leading scientists as a research programme rather than a theory. Aside from some of the programme’s underlying partial theories (dealing with such matters as macro- and microevolution and the molecular and genetic basis for the form and function of organisms), it has not been formalized, and there exist significant controversies as to its content and form (e.g. as to whether the development of new organisms has been more or less continuous or whether revolutionary changes such as the sudden development of completely different organisms have occurred)—as well as to whether the programme’s representations of organisms’ abilities to adapt, compete, cooperate and survive in fact represent a teleological perspective on the development of organisms. See e.g. (Depew and Weber 1996) and (Ward and Brownlee 2004).

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Pruzan, P. (2016). Hypotheses, Theories and Laws. In: Research Methodology. Springer, Cham. https://doi.org/10.1007/978-3-319-27167-5_3

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Scientific Theory Definition and Examples

A scientific theory is a well-established explanation of some aspect of the natural world. Theories come from scientific data and multiple experiments. While it is not possible to prove a theory, a single contrary result using the scientific method can disprove it. In other words, a theory is testable and falsifiable.

Examples of Scientific Theories

There are many scientific theory in different disciplines:

• Astronomy : theory of stellar nucleosynthesis , theory of stellar evolution
• Biology : cell theory, theory of evolution, germ theory, dual inheritance theory
• Chemistry : atomic theory, Bronsted Lowry acid-base theory , kinetic molecular theory of gases , Lewis acid-base theory , molecular theory, valence bond theory
• Geology : climate change theory, plate tectonics theory
• Physics : Big Bang theory, perturbation theory, theory of relativity, quantum field theory

Criteria for a Theory

In order for an explanation of the natural world to be a theory, it meets certain criteria:

• A theory is falsifiable. At some point, a theory withstands testing and experimentation using the scientific method.
• A theory is supported by lots of independent evidence.
• A theory explains existing experimental results and predicts outcomes of new experiments at least as well as other theories.

Difference Between a Scientific Theory and Theory

Usually, a scientific theory is just called a theory. However, a theory in science means something different from the way most people use the word. For example, if frogs rain down from the sky, a person might observe the frogs and say, “I have a theory about why that happened.” While that theory might be an explanation, it is not based on multiple observations and experiments. It might not be testable and falsifiable. It’s not a scientific theory (although it could eventually become one).

Value of Disproven Theories

Even though some theories are incorrect, they often retain value.

For example, Arrhenius acid-base theory does not explain the behavior of chemicals lacking hydrogen that behave as acids. The Bronsted Lowry and Lewis theories do a better job of explaining this behavior. Yet, the Arrhenius theory predicts the behavior of most acids and is easier for people to understand.

Another example is the theory of Newtonian mechanics. The theory of relativity is much more inclusive than Newtonian mechanics, which breaks down in certain frames of reference or at speeds close to the speed of light . But, Newtonian mechanics is much simpler to understand and its equations apply to everyday behavior.

Difference Between a Scientific Theory and a Scientific Law

The scientific method leads to the formulation of both scientific theories and laws . Both theories and laws are falsifiable. Both theories and laws help with making predictions about the natural world. However, there is a key difference.

A theory explains why or how something works, while a law describes what happens without explaining it. Often, you see laws written in the form of equations or formulas.

Theories and laws are related, but theories never become laws or vice versa.

Theory vs Hypothesis

A hypothesis is a proposition that is tested via an experiment. A theory results from many, many tested hypotheses.

Theory vs Fact

Theories depend on facts, but the two words mean different things. A fact is an irrefutable piece of evidence or data. Facts never change. A theory, on the other hand, may be modified or disproven.

Difference Between a Theory and a Model

Both theories and models allow a scientist to form a hypothesis and make predictions about future outcomes. However, a theory both describes and explains, while a model only describes. For example, a model of the solar system shows the arrangement of planets and asteroids in a plane around the Sun, but it does not explain how or why they got into their positions.

• Frigg, Roman (2006). “ Scientific Representation and the Semantic View of Theories .”  Theoria . 55 (2): 183–206. 
• Halvorson, Hans (2012). “What Scientific Theories Could Not Be.”  Philosophy of Science . 79 (2): 183–206. doi: 10.1086/664745
• McComas, William F. (December 30, 2013).  The Language of Science Education: An Expanded Glossary of Key Terms and Concepts in Science Teaching and Learning . Springer Science & Business Media. ISBN 978-94-6209-497-0.
• National Academy of Sciences (US) (1999). Science and Creationism: A View from the National Academy of Sciences (2nd ed.). National Academies Press. doi: 10.17226/6024  ISBN 978-0-309-06406-4. 
• Suppe, Frederick (1998). “Understanding Scientific Theories: An Assessment of Developments, 1969–1998.”  Philosophy of Science . 67: S102–S115. doi: 10.1086/392812

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This is the Difference Between a Hypothesis and a Theory

What to Know A hypothesis is an assumption made before any research has been done. It is formed so that it can be tested to see if it might be true. A theory is a principle formed to explain the things already shown in data. Because of the rigors of experiment and control, it is much more likely that a theory will be true than a hypothesis.

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.

What is 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 , 1859 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.") Elizabeth Kolbert, The New Yorker , 6 Aug. 2007

What is a Theory?

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 , 1839 An example of a fundamental principle in physics, first proposed by Galileo in 1632 and extended by Einstein in 1905, is the following: All observers traveling at constant velocity relative to one another, should witness identical laws of nature. From this principle, Einstein derived his theory of special relativity. Alan Lightman, Harper's , December 2011

Non-Scientific Use

In non-scientific use, however, hypothesis and theory are often used interchangeably to mean simply an idea, speculation, or hunch (though theory is more common in this regard):

The theory of the teacher with all these immigrant kids was that if you spoke English loudly enough they would eventually understand. E. L. Doctorow, Loon Lake , 1979 Chicago is famous for asking questions for which there can be no boilerplate answers. Example: given the probability that the federal tax code, nondairy creamer, Dennis Rodman and the art of mime all came from outer space, name something else that has extraterrestrial origins and defend your hypothesis . John McCormick, Newsweek , 5 Apr. 1999 In his mind's eye, Miller saw his case suddenly taking form: Richard Bailey had Helen Brach killed because she was threatening to sue him over the horses she had purchased. It was, he realized, only a theory , but it was one he felt certain he could, in time, prove. Full of urgency, a man with a mission now that he had a hypothesis to guide him, he issued new orders to his troops: Find out everything you can about Richard Bailey and his crowd. Howard Blum, Vanity Fair , January 1995

And sometimes one term is used as a genus, or a means for defining the other:

Laplace's popular version of his astronomy, the Système du monde , was famous for introducing what came to be known as the nebular hypothesis , the theory that the solar system was formed by the condensation, through gradual cooling, of the gaseous atmosphere (the nebulae) surrounding the sun. Louis Menand, The Metaphysical Club , 2001 Researchers use this information to support the gateway drug theory — the hypothesis that using one intoxicating substance leads to future use of another. Jordy Byrd, The Pacific Northwest Inlander , 6 May 2015 Fox, the business and economics columnist for Time magazine, tells the story of the professors who enabled those abuses under the banner of the financial theory known as the efficient market hypothesis . Paul Krugman, The New York Times Book Review , 9 Aug. 2009

Incorrect Interpretations of "Theory"

Since this casual use does away with the distinctions upheld by the scientific community, hypothesis and theory are prone to being wrongly interpreted even when they are encountered in scientific contexts—or at least, contexts that allude to scientific study without making the critical distinction that scientists employ when weighing hypotheses and theories.

The most common occurrence is when theory is interpreted—and sometimes even gleefully seized upon—to mean something having less truth value than other scientific principles. (The word law applies to principles so firmly established that they are almost never questioned, such as the law of gravity.)

This mistake is one of projection: since we use theory in general use to mean something lightly speculated, then it's implied that scientists must be talking about the same level of uncertainty when they use theory to refer to their well-tested and reasoned principles.

The distinction has come to the forefront particularly on occasions when the content of science curricula in schools has been challenged—notably, when a school board in Georgia put stickers on textbooks stating that evolution was "a theory, not a fact, regarding the origin of living things." As Kenneth R. Miller, a cell biologist at Brown University, has said , a theory "doesn’t mean a hunch or a guess. A theory is a system of explanations that ties together a whole bunch of facts. It not only explains those facts, but predicts what you ought to find from other observations and experiments.”

While theories are never completely infallible, they form the basis of scientific reasoning because, as Miller said "to the best of our ability, we’ve tested them, and they’ve held up."

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