The correct assessment of reaction kinetics, and the determination of reliable rate coefficients for reactions is often tedious and requires sophisticated methods. This is especially true for kinetic rate coefficients in radical polymerization. In polymerizations, to make it more complicated, rate parameters do not merely predict the rate of a polymerization. They also play a crucial role in the design and synthesis of novel materials since individual reaction rates influence the structure of a polymer. A meaningful prediction of monomer conversions, molecular weights, and polymer dispersities is only achievable if reactivity information of the monomers can be correlated with the rate coefficient of chain propagation and termination at minimum. The invention of the pulsed laser polymerization -size exclusion chromatography (PLP-SEC) method 35 years ago marked a turning point in investigations in polymerization kinetics by providing highly reliable measurements of propagation rate coefficients in a comparatively simple fashion. Over the years, a number of monomers has been investigated by this technique, and IUPAC working groups have benchmarked data for a number of important monomers. PLP-SEC allows for determinations with relatively high precisiontypically an error of 10 to 20 % is estimated. Yet, no unifying approach exists to date that correlates the structure of a monomer with its rate of propagation, and therefore no meaningful prediction of kinetic data can be made. Within specific families of monomers, most notably the (meth)acrylates, some trends are known. For example, theon first glance counterintuitive -increase of the propagation rate coefficient (kp) with the length of the ester side chain. Yet, already smaller differences in structure such as branching vs linear ester chains are not captured in the literature. The traditional way to predict kp is to use high level ab-initio quantum chemical calculation. While by themselves highly interesting, these calculations have for some monomers confirmed experimental values, but they struggle to make absolute predictions.