The study by Saavedra and Silverman (button phobia) was a case study.

Mark scheme

Marking points from the official mark scheme (Oct/Nov 2018). The mark or mark type is shown in brackets.

1. [2] Both marks are for outlining the term, examples only gain marks if they are part of the definition. 1st mark for either detailed or one instance/person 2nd mark for any of: detailed one instance/person of a rare / unusual condition may be longitudinal (can use) several different data collection methods (can use) triangulation an in-depth study of a single participant = 2 marks a very descriptive study of one unit = 2 marks
2. [2] Both marks are for one disadvantage. Points may be linked but do not have to be. one person is studied and they may be rare/unique/unusual = 1 mark so researchers are less likely to be able to generalise to the wider population / less representative = 2nd mark reliability may be a problem because the researcher may be subjective and vary their interpretation = 2 marks the researcher may be get to know the participant well (making their interpretation / data collection) subjective = 1st mark which would make the data invalid = 2nd mark