Outline two variables within restaurant that were controlled, other than the music CDs.
Syllabus: 2.1.2 Key study on musical style and restaurant customers' spending: North et al. (2003).
Marks: Award 1 mark for each outline.
Definitive answers:
- lighting (was kept at the same levels throughout the study)
- decoration (was not changed)
- temperature (was maintained at a constant temperature)
- menu (was not changed, such as an increase in prices, or items)
- the waitress, gathering data, was always the same
Note: any other aspect scores no marks (especially music).