Nuffield Primary History

TWENTY FIRST CENTURY SCIENCE
Ideas about Science: Glossary

Here is a teachers’ glossary of ‘Ideas about Science’ terms compiled by the C21 team. This glossary clarifies the way these terms are used in the OCR GCSE Science specification and OUP resources.

Note that ‘Ideas about Science’ is the term used in this course; they fully cover the QCA requirements for teaching ‘How Science Works’.

Students should learn these ideas from experiencing examples in different contexts. This list is not intended for students.

Accuracy How close a measurement of something is to its true value.

ArgumentStatements offered in support of your conclusion or opinion.

Benefits and costs When you do anything, it may make some things better. These are the benefits. But it may also make some things worse. These are the costs.

Best estimate When you measure something, you cannot be sure you have found its true value. There is always some uncertainty in measurements. All you can do is say what you think the true value is most likely to be – your ‘best estimate’.

Correlation A pattern in the data about two things that suggests they are linked. For instance, when ice cream sales rise, the level of hay fever also increases.

Cause When two things are correlated and there is a reason to explain how one leads to the other (a mechanism).

Conclusion The answer you can give to a question – based on data (or evidence) and argument.

Control A sample that has not been given the treatment you are testing, or has not been exposed to the factor you are investigating. You can compare the control with a sample that has been given the treatment.

Data Pieces of information about a process or object. Good data are both valid and reliable.

Ethics Rules about how to behave, based on what is right and what is wrong.

Evidence Data used to support an argument, conclusion, or explanation.

Experiment A practical procedure, carried out to collect data to test a hypothesis.

Explanation A series of linked statements, or story, that accounts for something happening. An explanation can only be called ‘scientific’ if it is accepted by a group of other scientists.

Factor Anything that can affect something else. For instance, the temperature of the air affects how much you sweat.

Hypothesis A suggested explanation for how something happens. A hypothesis is usually based on observations.

Mean An average from a set of data. (The mean is worked out by adding up a set of measurements, then dividing by the number of measurements.)

Mechanism A description of how a factor causes an outcome (a cause leads to an effect).

Observation Something you can say about the world, based on information from your senses.

Outcome Something that happens because of other things happening. A change in one of these other things (factors) can lead to a change in what happens. For example: ‘The temperature of the air increases. One outcome of this is that your body makes more sweat.’

Outlier A measurement that does not fit the pattern of other data collected.

Peer review Scientists publish their data and explanations as articles in journals. Before they are published, other scientists read the articles. They evaluate the way the scientist has done their work, the quality of their data, and how good their explanation is. This is peer review. If other scientists think the work is good, then it is more likely to be published.

Prediction What you think will happen in a particular situation. Predictions are based on current explanations for how something works. For example: If the mass on the spring is doubled, the extension of the spring will double.

Range The lowest to the highest of a set of measurements. For example, in 24 hours the range of John’s heart rate was 50–125 beats per minute.

Real difference A difference which is too big to be put down to chance. You can be fairly sure that the difference between two mean values is real if their ranges do not overlap.

Regulations Rules made by an authority, such as the Government. For example, all motor vehicles over three years old must have a MOT test.

Reliability When repeated measurements of the same thing are close to each other, the data is reliable. You can have more confidence in conclusions and explanations if they are based on reliable data.

Replication Repeating something. For example, taking two or three measurements of the same value in an experiment.

Risk The chance of something happening, and the consequences if it does.

Perceived risk What a person thinks the risk is.
Actual risk A risk based on collected data about outcomes in similar circumstances
Precautionary principle Choosing not to do something when you don’t know how big the risk is, but the consequences (if it does happen) are serious. This is sometimes described as being ‘better safe than sorry’. For example: ‘You want to go swimming in a river. You cannot see below the surface, so you decide not to jump in. There could be sharp rocks close to the surface. You get in slowly and carefully.’
ALARA –“As Low As Reasonably Achievable”. When we identify a risk, we can sometimes make changes to make things safer. But nothing can be completely safe. For example: ‘You are exposed to radiation when you have an X-ray. The amount of radiation used is the smallest amount needed to make the X-ray picture.’

Sample A group taken from of a population.

Sample size How many there are in a sample.

Scientific community A group of scientists who work in the same field. They may share ideas, and discuss each others’ work.

Technical feasibility Something that it is possible to do. This does not mean it should be done.

Validity A measurement is valid if it measures the thing it is supposed to be measuring.

Variable A quantity that may change, e.g. the temperature of the air.

Input variable The quantity that changes, e.g. temperature of water.

Outcome variable The quantity that is affected by the input variable. For example, how quickly a teaspoon of sugar dissolves in the water.

Twenty First Century Science

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