It is correct to give the live load participation coefficient from the floor parameters dialog... because if you calculate it yourself (by multiplying the coefficient with the live load) and assign it to the floors, the loads you assigned in the floor parameters dialog will be multiplied again at the coefficient ratio... Ex: Q=200 kg/m2 ; If n=0.3, nQ=60 kg/m2.... if you throw this load on the floor, the coefficient of participation in the floor parameters will participate in the analysis and calculate this load value as 0.3*60=18 kg/m2. You can consider entering the participation coefficient as 'n=1' among the floor parameters and calculating and assigning the Q values on the floors yourself, but I don't think it is a very consistent approach... My suggestion is to define the floor parameters and assign your live loads as they are... good work, respect...