1. Sampling

2. Methods of sampling Simple random sampling Systematic sampling Stratified sampling

3. Random sampling The sample is formed by selecting members of a population at random. Tables of random numbers can be used or a scientific calculator. Each member of the population must have an equal chance of being selected.

4. Systematic sampling This type of sample is formed by selecting the members of a population at regular intervals. EG select every 5 th person from a class register.

5. Stratified sampling The population is split into groups e.g. gender or age. The groups in the sample must be in the same proportion as the population.

6. Questions For the following situations describe how you choose a sample, referring to which sampling method you would use. Give a reason for your choice.

7. Jerry does a survey on favourite chocolates. He stands outside the Cadburys factory in Birmingham at 5pm on a Friday.

8. Jack wants to do a survey on fitness & exercise where he lives. Alan wants to find out about favourite pop groups in his school (1200 pupils).

9. Jean wants to investigate if tabloid newspapers have more pictures than broadsheets Andy does a survey on heights & weights of people in his school

10. Joe wants to find out how many people are in his year