The lead time varies depending on the difficulty of the recruitment conditions.
For a simple criteria(High incedence rate), recruitment will start at least 10 days to 2 weeks in advance. Central Location Test(CLT) is often requied several days rather than just one day and is conducted over multiple days due to the quantitative. Hence, it is requiring scheduling adjustments period.
Regarding the screener, all time slots for the entire survey period are presented, and participants are asked to select all available slots they can participate. Before inviting applicants who meet the criteria to participate, there is a schedule allocation. With the need for scheduling adjustments for hundreds of people, sending a screener → selection → schedule adjustment → formal invitation (notification), an early start is desirable.
While it may seem that the earlier, the better, starting recruitment a month in advance may lead to cases where participants cancel due to last-minute business trips or unavoidable school events for children. It’s best to request when the schedule can be somewhat predicted and confirmed, such as next week to the week after next.
However, there may still be cases where “we’d like to recruit participants for next week due to a sudden project decision”. We can accommodate such urgent requests, so please feel free to contact us. In such cases, rather than setting the slots at the last minute, it would be helpful to provide some backups, making it easier to adjust the schedule.