The scientific method
Select Lesson
Exam Board
Select an option
Physics practicals
Investigating the specific heat capacity
Investigating the resistance of a length of wire
Investigating I-V characteristics
Investigating series and parallel circuits
Investigating the densities of solids and liquids
Investigating elasticity
Investigating force and acceleration
Investigating waves in different materials
Investigating infrared radiation
Magnetism and electromagnetism
Waves
Forces
Atomic structure
Particle model of matter
Electricity
Energy
Working scientifically
Explainer Video
Summary
The scientific method
In a nutshell
Observations, hypotheses and theories underpin the scientific methods that scientists use.
Hypothesis
Definition
A hypothesis is a scientific explanation for an observed event. Although hypotheses may be based on existing scientific knowledge, there is no specific, sufficient evidence for a hypothesis.
Tip: The plural for hypothesis is hypotheses.
Testing a hypothesis
Predictions can be made based on a scientific hypothesis. These predictions can be tested by designing and carrying out scientific experiments. The outcome of the experiment may support or contradict the hypothesis.
Evidence supporting a hypothesis must be peer-reviewed. A peer-review is an unbiased evaluation carried out by other scientists to review the appropriateness of a scientific investigation. Scientists check if:
- The scientific research is valid.
- The scientific research is original.
- The scientific research is significant.
Valid research is repeatable and reproducible. An investigation is repeatable if the same /similar results are achieved when the scientist repeats the experiment. An investigation is reproducible when another scientist carries out the experiment and also gets the same/similar results.
Accepting or rejecting a hypothesis
In order for a hypothesis to be accepted, there must be sufficient evidence.
- Logical, specific experiments must be designed
- Multiple scientific experiments need to be carried out
- Scientific experiments must be carried out by many different scientists
- All supporting evidence must be peer-reviewed
- Evidence which contradicts the hypothesis must be taken into consideration
Theory
Definition
A scientific theory is an evidence-based scientific explanation. Theories are based on accepted hypotheses.
Models
A model is a simplified representation of a theory. Scientific theories are complex and sometimes difficult to understand. Scientific models are helpful in understanding theories, since they are simplified representations.
Example
Bohr model of an atom.
The diagram above depicts an aluminium atom based on the Bohr model.
FAQs - Frequently Asked Questions
What is the plural for hypothesis?
The plural for hypothesis is hypotheses.
What is a peer-review?
A peer-review is an unbiased evaluation carried out by other scientists to review the appropriateness of a scientific investigation.
What is a theory?
A scientific theory is an evidence-based scientific explanation. Theories are based on accepted hypotheses.
What is a hypothesis?
A hypothesis is a scientific explanation for an observed event. Although hypotheses may be based on existing scientific knowledge, there is no specific, sufficient evidence for a hypothesis.