Bias in science

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Key points

  • Scientific studies can be biased and it is important to recognise when this is the case.
  • Try to avoid bias when following the scientific method and drawing conclusions in investigations.
  • Scientists review each other's conclusions from new scientific research. They also check the method used and the accuracy of the results. This is known as peer review.


Watch this video about identifying and avoiding bias in science.

While you are watching, look out for the common clues that show bias could be present in the information

Bias in data

is a word often used to describe a point of view. This view might not take into account all available evidence.

Results from science investigations can also be biased if there is something wrong with the equipment or method.

Scientific measurements taken can be affected by two types of error that may make results biased:

  • : This can alter the spread of data and cause . One reason could be that the person doing the experiment uses the equipment or takes the reading incorrectly. Another reason could be a variable that couldn’t be controlled, like a temperature drop in the room.
  • : This can make measurements less . It may happen if equipment is not used properly and can cause all results to differ by the same amount, eg timing using a stopwatch that hasn't started from zero.

As well as spotting bias in , when drawing a conclusion it is important to be able to spot bias in . Checking the method used and checking the range of data can help to identify bias.

As well as the range of data, what else should be checked to help to spot bias?

The method should be checked as well as the range of data.

Bias in language

can be used to highlight a point of view and persuade someone to agree with it.

The person or organisation sharing the information might be trying to persuade people that their view is correct, but may not present all the evidence or information that contradicts their viewpoint.

For example, some people deny that human activity speeds up . However, the vast majority of (97%) agree that the evidence supports the understanding that burning fossil fuels is directly linked to climate change.

True or false?

An organisation sharing information that takes into account all reliable evidence is likely to be biased.

False. If all available reliable evidence has been taken into account, then the information will not be biased.

Wherever information is gathered from to help inform opinions, it's important to consider the words being used and understand if the information is valid.

Peer review

Scientists across the world form a scientific community. For scientists, their are other scientists.

Conclusions from new scientific research are reviewed or checked by other scientists. They check the method used, the accuracy of the results and the conclusions drawn.

Scientists check that the research is and . In doing this, scientists help to make sure that bias has been avoided. This helps other scientists and non-scientists across the world have confidence in what they are reading or are being told about.

Who are scientists' peers?

Other scientists working in the same area of science.

Did you know?

In 1998, a medical study suggested a link between the and . As a result of this, MMR vaccination rates in the UK dropped. The study has now been completely discredited.

The 1998 research didn't take into account all available evidence and information. For example, over the time period that the study was done, it didn’t consider population increase. The results from this study misled a lot of people.

The MMR vaccine

Test your knowledge

Quiz - Bias in science