Scientific Evidence
Contents
Key Stage 2
Meaning
Scientific Evidence is the observations and measurements a scientist gets from an investigation.
About Evidence
- There are different kinds of evidence but scientists don't trust all of them.
- In science evidence must be repeatable. If you make an observation or measurement once, you should be able to do it again and again and the results shouldn't change.
- In science evidence must be reproducible. So if one scientist makes an observation or measurement, every other scientist in the world should be able to make the same observation. If they cannot; then scientists don't accept it as scientific evidence.
Examples
| Claim | Evidence |
| Plants need water to live. | Plants in dry soil wilt and then die. |
| Paper is flammable. | When you place a flame under paper the paper catches fire. |
| Cats are mammals. | They have fur, they give birth to live babies, they feed their babies with milk. |
Key Stage 3
Meaning
Scientific Evidence is the observations, readings or measurements that a scientist will use to test whether a hypothesis is correct.
About Evidence
- There are different kinds of evidence but scientists don't trust all of them.
- In science evidence must be repeatable. If you make an observation or measurement once, you should be able to do it again and again and the results shouldn't change.
- In science evidence must be reproducible. So if one scientist makes an observation or measurement, every other scientist in the world should be able to make the same observation. If they cannot; then scientists don't accept it as
scientific evidence.
- Stories, or observations made by non-scientists, that cannot be repeated are called anecdotal evidence which is not accepted by scientists because people could have made a mistake or be lying.
Examples
The Earth is Round: Observation - The tip of a mast always appears before the rest of the ship on an ocean. Measurements - On the 23rd of June a stick at the equator has no shadow. In Alexandria the shadow is 3cm long, in Paris it is 5cm long and in London the shadow is 8cm long.
Key Stage 4
Meaning
Scientific evidence is any observations or results that are repeatable, reproducible and valid to prove or disprove a hypothesis.
About Scientific Evidence
- Scientific evidence is intended to be objective which means anyone can observe the same evidence regardless of their beliefs.
- Scientific evidence is gathered following a set of practices designed to reduce the bias of the person performing the investigation.
- Scientific evidence is not the same as the evidence used in a court of law.
- Some forms of 'evidence' are not accepted by scientists, including:
- Anecdotal Evidence - 'Evidence' based on a personal experience. Scientists don't trust this because people can make mistakes, misunderstand something they've seen or even hallucinate or dream things which have not happened.
- Intuition - Ideas that seem true because they make sense are not counted as scientific evidence. Just because something seems reasonable, interesting or makes sense does not mean it is true.
- Tradition - Ideas that have been passed on through generations. Just because many people say something is true, doesn't mean it is true. Such ideas were usually made thousands of years ago at a time when the wheelbarrow would have seemed like a state of the art invention and most people believed disease was caused by demons.