FractionalFactorial does not have any keyword arguments.
Fractional Factorial method creates a design matrix by utilising Hadamard Matrix and uses it run simulations of the input model. The main effects are then evaluated by dot product between the contrast for the parameter and the vector of simulation results. The corresponding main effects and variance, i.e. square of the main effects are returned as results for Fractional Factorial method.
function gsa(f, method::FractionalFactorial; num_params, p_range = nothing, kwargs...)
using GlobalSensitivity, Test f = X -> X + 2 * X + 3 * X + 4 * X * X res1 = gsa(f,FractionalFactorial(),num_params = 12,N=10)