Difference between Observation, Theory and Law

Key Difference: In philosophy of science, observation, theory and law, all play important roles. Observation is generally regarded as an act to sense the external real objects. Sense organs play a vital role in the observation. Theory can be described as a scientific explanation of an observed activity or a phenomenon. It explains the observations or events that are based upon any proven hypothesis. A law is a description of an observed phenomenon or activity. It is generally regarded as a statement of fact.

An observation is considered to be an act to sense the external objects. An observation is regarded to be free of any pre-held assumption. Therefore, it is rarely objective. The term observation is generally used in context to information gathering.

Theory is the explanatory version of the facts and accounts for the observations. Theory is considered to contain the knowledge and explanatory concepts. It is accompanied by reasonable explanation or facts. Thus, considerable evidence is very important for formulating any kind of theory.

A law describes what nature does under certain conditions and also predicts the outcome as long as the conditions are met. It is also referred to as a statement of fact that is accepted as the absolute truth. It is based on the generalized principle that appears to be true at the time it was made or formulated, without any exception. It is important to mention that even laws may be challenged in the future.

Some of the differences are listed below:-

	Observation	Theory	Law
Type	Details of the resulting perceptual experience.	Coherent, systematic, predictive, and broadly applicable.	Short and true. Generally, expressed in a single expression.
Features	Focus on behavior No manipulation with the observed entity Accurate noting of the phenomenon Basic method of information gathering Scientific or non- scientific in nature	Internally consistent and compatible with the evidence Firmly grounded in and based upon evidence Tested against a wide range of phenomena Demonstrably effective in problem-solving	Applied under the same conditions. Scientific laws are empirical truths. Laws are generally universally accepted.
Examples	A scientist looking at a chemical reaction in an experiment A doctor watching a patient after administering an injection	The theory of evolution The heliocentric theory of the solar system	Law of conservation of mass-energy 2nd Law of Thermodynamics
Importance	Useful in establishment and confirmation of a Hypothesis	Very broad applications and explanatory power.	General Universal Acceptance
Questions/Answers	Basis of formulation of questions and answers.	Explains the answer to question like- why things are the way they are.	Description of result of repeated observation. So, can be just answer the description related to the result of repeated observations.