Item B: A researcher sends a structured questionnaire to 500 pupils across ten schools chosen by the researcher's contacts, and receives 320 responses. The researcher reports the findings as if they represent all pupils in the city.
(a)Using Item B, identify two features of the sample or method that might make the sample unrepresentative of all pupils in the city.(2)
(b)Using Item B, explain one way the researcher could improve representativeness when sampling pupils in the city.(2)
(Total for Question 8 is 4 marks)