Effective model-free parameters as a function of the true timescale for conformational exchange, τe true = (k 1 + k 2)−1. Colors correspond to pairs of states with different rotational constants. (Left) Effective global tumbling time, τc eff = 1/6D eff. (Center) Effective internal correlation time, τe eff = 1/2k eff. (Right) Effective order parameter, 𝓢 eff 2. In all cases, p eq(1) = 0.3, n 1 = n 2.