Examples of what pupils should know and be able to do
Pupils should be aware that for an investigation into heights and weights it would not be appropriate to measure and weigh a random group of pupils arriving at school.
Probing questions
Who should you ask?
Why would you ask that group of people?
Is there anybody else who might be included?
Are there any reasons why they may not answer honestly?
What if pupils find this a barrier?
Use data collection sheets to demonstrate how bias can be introduced through poor and insufficient questioning. Show how inappropriate sampling can introduce bias.