The sample size depends on the number of ideas and the number of tasks that each respondent will see.
Deciding principles are:
- Minimum exposure per idea for the screening tasks is 100.
- No consumer reviews more than 2 ideas in detail.
Recommended minimum sample sizes:
| Number of Ideas: | 5 | 10 | 20 | 30 | 40 | 50 |
| Total sample size: | 200 | 375 | 750 | 1125 | 1500 | 1875 |