Instationary polymerization technique (IPT) is a combination of nonstationary polymerization conditions and the controlled deactivation of all active radicals present in the system by reaction with an inhibitor at a certain time span after initiation. The special features of the resulting molecular weight distribution can be used for the direct determination of k(p) in analogy to the pulsed-laser polymerization (PLP) method. Furthermore, a qualitative information about the prevailing termination mechanism - i.e. disproportionation or combination - is also feasible from the distribution at a first glance.