In research on beamed energy propulsion, the momentum coupling coefficient c_m is a central figure of merit to characterize a propulsion system. The determination of c_m is based on the measurement of imparted impulse and laser pulse energy. Nevertheless, the knowledge of laser pulse length, laser spot area and ablated mass is of great importance for the comparability of experimental results in laser ablative propulsion. The use of a great variety of measurement techniques for these parameters throughout the scientific community implies the risk of misunderstandings and might impede the comparability of results. In this paper, we present critical issues concerning the measurement of the aforementioned key parameters with respect to possible standardization issues. As an example, a simple laser propulsion experiment will be presented and compared with an experimental model from a different research group.