Jodie is investigating attitudes to doodling in class. She wants to obtain a sample that includes students and teachers.

Mark scheme

Marking points from the official mark scheme (May/June 2020). The mark or mark type is shown in brackets.

1. [1] (a) Most likely: opportunity = 1 mark OR Volunteer = 1 mark.
2. [2] (b) 1 mark for description of use; 1 mark for link to Jodie's study (including teachers and students). Opportunity: use people who are available (e.g. the students and teachers in her classes). Volunteer: allow people to self-select / put up adverts for participants to respond to (e.g. put up notices in school asking for teachers and students to respond).
3. [1] (c) 1 mark for simple linked advantage. Opportunity samples are easy to collect so Jodie should be able to find a big sample of students and teachers (making her results valid/generalisable). OR Volunteers are likely to be willing (e.g. to talk about doodling) / Students often have free time so are likely to volunteer.
4. [3] (d) 1 mark for identifying a problem (must be implicitly or explicitly linked to Jodie's study); 1 mark for explaining it OR for explaining why the other technique is better; 1 mark for identifying an alternative sampling technique. Opportunity: (limited to available people) so likely to be similar / lack variety (e.g. the students and teachers might not be typical of those in all subjects/schools) use volunteer sampling instead (e.g. a volunteer sample from school could include students and teachers of all ages). OR Volunteer: (limited to people who respond) may all be very willing / educated (e.g. they might not be typical of those in other schools) use random sampling instead (e.g. a random sample from school would include students and teachers of all ages).