An important task in the field of environmental risk assessment (ERA) is to test whether new varieties have a similar effect on the environment as appropriate, conventional counterparts (EFSA 2010). To address this issue, field trials are designed to compare new varieties with their conventional counterparts (comparators) with respect to the effect on abundance of non-target organisms (NTOs). Using statistical testing, for each NTO measurement unit (or endpoint) it can be determined whether both varieties have a similar effect on the abundance. With the Amiga Power Analysis tool, you can calculate the necessary replication for assessing differences and equivalences between a test and a comparator plant variety under different data models for count and continuous data.