A psychologist is investigating the effectiveness of a cognitive-behavioural anger management program in a young offender institution. She administers a newly designed questionnaire to the offenders to rate their own anger levels after completing the course. She also obtains the institution's official registers recording the number of behavioral infractions each offender committed prior to starting the program.
Referring to this study, explain the difference between primary and secondary data.
235 exam-style questions on AQA A Level Psychology Data handling and analysis. Each one has a worked solution and a mark scheme showing where the marks go.