When it comes to scientific theories, there are certain criteria that must be met in order for a theory to be considered valid. In this article, we’ll explore the four things needed to have a scientific theory.

Observations and Data

The first thing that is needed to develop a scientific theory is observations and data. Without these, there can be no basis for any kind of explanation or theory. Scientists must observe natural phenomena and gather data to support their observations.


Let’s take the example of Sir Isaac Newton observing an apple falling from a tree. He noticed that the apple always fell towards the ground and never flew upwards. This observation led him to develop his theory of gravity.


Once scientists have gathered enough data, they can begin developing hypotheses. Hypotheses are testable explanations for observed phenomena. They are often based on previous observations but must be testable through further experimentation.

Using our previous example of Newton’s observation of the apple falling from the tree, he developed the hypothesis that all objects are attracted to each other with a force proportional to their mass and inversely proportional to the square of their distance apart.


After developing a hypothesis, scientists must make predictions based on that hypothesis. These predictions should be testable through further experimentation and should help support or disprove the hypothesis.

For Newton’s hypothesis on gravity, he predicted that if an object was dropped from a certain height, it would fall towards the ground at a certain rate of acceleration which could be measured.

Testing and Refining

Finally, in order for a scientific theory to be considered valid it must undergo extensive testing and refinement. Scientists must continuously test their hypotheses and predictions under different conditions in order to refine their theories.

Newton’s theory of gravity underwent extensive testing and refinement over the years. Other scientists, such as Albert Einstein, proposed new theories based on Newton’s initial observations which led to further refinement of the theory of gravity.

By following these criteria, we can develop a better understanding of the natural world around us and continue to expand our knowledge in various fields of science.