Lesson Progress:

What is Science?

Lesson Content

Inquire: The Importance of Science


During this lesson, students will learn the definition of science and how scientists use induction and deduction processes when they conduct scientific investigations. Induction and deduction are both important concepts to understand as they are the basis for the scientific method and scientific research. We will explore and identify the differences between scientific theories and laws, as well as establish a brief introduction to the history of science and the diverse contributions made by different individuals.


Big Question

Can you find examples that illustrate the differences between scientific theories and scientific laws or deduction and induction?

Watch: Scientific Theories & Laws

Read: What is Science?


DecorativeScience encompasses a variety of fields that include physics, chemistry, astronomy, biology, computer sciences, geology, logic, and mathematics.

What is science? Science (from the Latin scientia, meaning “knowledge”) is defined as knowledge that covers general truths or the operation of general laws. More precisely, science consists of the theories and laws that are the general truths of nature as well as the body of knowledge they encompass. Science is not a collection of facts that you can memorize and recite, it is a way of investigating and analyzing the world around us. Science is not just having knowledge but making useful contributions to the scientific body of knowledge. Scientists are continually trying to expand this body of knowledge and to perfect the expression of the laws that describe it.

We will explore how logical induction helps scientists conduct investigations and change what we know about the world. We will also discuss the differences between scientific theories and scientific laws, as well as examine some major contributions made in the field of science.

Scientific Investigations

DecorativeScientific investigations are primarily based on inductive reasoning or induction. Induction is a form of logical thinking that uses related observations to arrive at a general conclusion. For example, let’s assume you know nothing about gravity. Perhaps you notice that whenever you let go of an object it falls to the ground, or when you drop a book it crashes to the floor. Your pencil rolls to the edge of the desk and down it goes. You throw a ball into the air, and it falls back down. Using induction, you conclude that all objects fall to the ground.

Scientific Theories and Laws

Investigations like the one above are how scientists draw conclusions, hypothesize theories, and build on scientific laws. After enough individuals independently test the hypothesis that all objects fall to the ground, it becomes a scientific theory.

A scientific theory is a scientific hypothesis that has been tested and proven through repeated experiment and data. Examples of theories in physical science include Dalton’s atomic theory, Einstein’s theory of gravity, and the kinetic theory of matter.

Scientific laws are supported by scientific evidence and repeated experiments. They use concise language to describe a generalized pattern in nature. Typically, a law can be expressed in the form of a single mathematical equation.

Laws and theories are similar in that they are supported by scientific evidence and are both scientific statements that result from a tested hypothesis. The designation law is reserved for a concise and very general statement that describes phenomena in nature, such as the law that energy is conserved during any process, or Newton’s second law of motion, which relates force, mass, and acceleration by the simple equation F=ma. A theory, in contrast, is a less concise statement of observed phenomena. The theory of evolution and the theory of relativity cannot be expressed concisely enough to be considered a law. The biggest difference between a law and a theory is that a theory is much more complex and dynamic. A law describes a single action and doesn’t explain why it happen. A theory explains an entire group of related phenomena and can answer the “why” questions.

The History of Science

As a species, we have wondered about the world for as long as we have been on Earth. As a result, modern science goes back thousands of years. While we cannot cover the entire timeline of science in detail in this lesson, you can research further by using the links provided in the Toolbox.

Contributions to the Body of Knowledge

DecorativeAn important component of science is ensuring that people add information to the overall body of knowledge. The following scientists have used their research to further our understanding of the world around us. Thales (600 BCE): This ancient Greek philosopher was one of the first to hypothesize that natural events, such as lightning and earthquakes, had natural, explorable causes. He has been called the “Father of Science” because of his ideas about the natural world.

Aristotle (350 BCE): Aristotle created the first iteration of the scientific method by arguing that the natural world could be studied and understood through observation and induction. Observation and induction are two of the foundational ideas in the current scientific method.

Galileo (mid-1500s to late-1600s): Galileo vastly improved telescopes and used those improvements to redefine and revolutionize astronomy.

DecorativeMarie Curie (1867-1934): Marie Curie was the first woman to win a Nobel Peace Prize. In 1903, she discovered radiation. In 1911, she discovered the elements Radium and Polonium. For both of these contributions, she received Nobel Peace Prizes.
Lise Meitner (1878-1968): Meitner discovered nuclear fission, the process by which splitting atoms yields tremendous amounts of energy. We currently use these processes in nuclear power plants around the world.
Irene Joliot-Curie (1897-1965): The daughter of Marie Curie, Irene Joliot-Curie and her husband, Frédéric Joliot-Curie, won the Nobel Peace Prize for their contributions to chemistry with their discovery of synthesis of new radioactive elements.

Maria Goeppert-Mayer (1906-1972): Co-winner of the 1963 Nobel Peace Prize for her work on the structure of atomic nuclei.

Reflect: Induction or Deduction?


Although induction and deduction are used by most sciences, they can also be applied to everyday situations. Think about a problem that you may have at school, at home, or with your car, and apply inductive or deductive reasoning to solve. Reflect on the following scenario:

You jump in the car to meet your friend for coffee and turn the key, but the car will not start. You try a few more times, but nothing happens. You undoubtedly wonder “what’s going on, why will the car not start?” Then you may do some online research, ask your family or call your friends to learn about a variety of reasons why the car will not start. You may believe that the car is not starting because it has no engine oil.

To test this, you open the hood of the car and check the oil level. In this troubleshooting process, which type(s) of reasoning do you apply?

Expand: Induction & Deduction in Science and Daily Life


Scientists seek to understand the world and the way it operates. To do this, they use two types of reasoning: inductive reasoning (induction) and deductive reasoning (deduction).


As previously discussed, induction is a type of reasoning that draws conclusions based on many different individual observations. Induction works by beginning with an initial observation, then comparing subsequent observations to the initial one in order to uncover patterns. Using this sequence of patterns, scientists make a generalization and create a hypothesis or a theory, which are “If-Then” statements.

There are lots of induction examples in everyday life. For example, assume you spend the summer break in a small town and the six people you meet are friendly, so you inductively conclude the following: “Everybody in this small town is so nice.”

DecorativeInduction cannot prove conclusively that an idea is true; however, an effective way to enhance the possibility an idea is true is to constantly observe and hypothesize over a substantial period of time, often decades. Take the example that you conclude all objects fall to the ground. One day, you see round objects (balloons) rising up into the sky rather than falling toward the ground as you would expect. Your first conclusion—although based on many observations and evidence—is now incorrect. You need to gather more evidence to come to a new conclusion that can explain all of your observations.


Deduction is the narrowing from a broad theory to a concept, essentially the opposite of induction. Deduction begins with a broad theory, then creates a tentative hypothesis, still in the “If-Then” form, to capture quantifiable data that researchers then use to form additional hypotheses about the phenomenon. From this repeated experimentation, the researchers observe patterns that shape our understanding of the theory in question. Studies in climate change can illustrate this type of reasoning. Scientists may predict that if the climate becomes warmer in a particular region, then the distribution of plants and animals would change. These predictions have been made and tested, and many such changes have been found.

There are lots of deduction examples that can found in everyday life. Take the small town example previously mentioned. You inductively conclude the following: “Everybody in this small town is so nice,” then you deductively conclude that the next people you meet in this town will be nice also. Other examples can include, being careful around bees because they may sting you or reasoning that if you have to pick up your friend at the airport and it takes you an hour to get there, you would leave at nine o’clock to arrive at the airport at ten o’clock. All of these examples use deduction to better understand the world around us.

DecorativeThere is no right or wrong method when it comes to using induction or deduction to conduct scientific experimentation. Both of these methods are vital to improving and changing our understanding of the world around us. Induction has its place in the scientific method when scientists use it to form hypotheses and theories. Deduction allows them to apply the theories to specific situations. There is a constant interplay between induction (based on observation and hypotheses) and deduction (based on theory), as we get closer and closer to the ‘truth.’

Check Your Knowledge

Use the quiz below to check your understanding of this lesson’s content. You can take this quiz as many times as you like. Once you are finished taking the quiz, click on the “View questions” button to review the correct answers.

Lesson Resources

Lesson Toolbox

Additional Resources and Readings

Science Timeline

A complete history of science

Induction and Deduction

Further explanation about induction and deduction

What Is a Law in Science?

Further explanation of the differences between scientific laws and theories

Non-Traditional Careers for Science Majors | Dr. Dwight Randle | TEDxMountainViewCollege

A video describing non-traditional and intriguing careers for science majors

Lesson Glossary


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  • Dalton’s atomic theory
    proposes that all matter is composed of atoms, indivisible and indestructible building blocks. While all atoms of an element are identical, different elements have atoms of differing size and mass. It also postulates that chemical reactions resulted in the rearrangement of the reacting atoms.
  • deduction
    a form of logical thinking that narrows a broad theory into a concept
  • induction
    a form of logical thinking that uses related observations to arrive at a general conclusion
  • kinetic theory of matter
    states that matter is composed of a large number of small particles—individual atoms or molecules—that are in constant motion. This theory is also called the kinetic-molecular theory of matter and the kinetic theory of gases.
  • science
    knowledge that covers general truths or the operation of general laws, especially when acquired and tested by the scientific method
  • scientific law
    a generalized pattern in nature that is supported by scientific evidence and repeated experiments that is described using concise language
  • scientific method
    method of research with defined steps that include observation, formulation of a hypothesis, testing, and confirming or falsifying the hypothesis
  • scientific theory
    tested and confirmed explanation of natural phenomenon using research over an extended period of time
  • theory of evolution
    first formulated in Darwin's book, "On the Origin of Species," in 1859, it is the process by which organisms change over time as a result of changes in heritable physical or behavioral traits. Changes that allow an organism to better adapt to its environment will help it survive and have more(...)
  • theory of relativity
    usually encompasses two interrelated theories by Albert Einstein: special relativity and general relativity. Special relativity applies to elementary particles and their interactions, describing all their physical phenomena except gravity. General relativity explains the law of gravitation and(...)

License and Citations

Content License

Lesson Content:

Authored and curated by Ja’Corie Maxwell, Jinxiu Yuan for The TEL Library. CC BY NC SA 4.0

Adapted Content:

Title: 1.1 The Science of Biology: Rice University, OpenStax CNX. License: CC BY 4.0

Title: 1.1 Physics: An Introduction: Rice University, OpenStax CNX. License: CC BY 4.0

Title: Physical Sciences Grade 12 – 1.1 The development of a scientific theory. Siyavula Science; Siyavula Education. License: CC BY 3.0

Media Sources

DecorativeScienceAndrey MitinFlickrCC BY 2.0
DecorativeQualitative vs QuantitativeJaime AnsteeWikimedia CommonsCC BY 4.0
DecorativeBalloons IIjayneanddFlickrCC BY 2.0
DecorativeIrène Joliot-Curie HarcourtHarcourtWikimedia CommonsCC BY 4.0
DecorativeIllustrerad Verldshistoria band I Ill 107Ernst Wallis et alWikimedia CommonsPublic Domain
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