AbstractWith the high interest in improving the performance of electrocatalysts for technologically significant reactions, great efforts are directed at the assessment of the activities of various catalytic materials. For this purpose, it is important to compare the catalytic activities measured using different methods and under different conditions. To achieve this, it is of utmost importance to avoid certain methodological and instrumental issues that can severely affect the obtained experimental results. Using well‐defined systems, we demonstrate the importance of experimental conditions in the assessment and benchmarking of the activity of catalytic processes for various reactions. Particularly, we demonstrate that the correction of the uncompensated ohmic resistance using impedance spectroscopy measurements requires particular attention and additional procedures which are normally ignored. Additionally, we demonstrate how the uncompensated resistance changes with the potential if a non‐conducting gas phase is accumulated in the system, hence influencing the activity measurement. It is further shown that a correct choice for surface‐limited reactions for the determination of the real surface area of catalytic electrodes plays a key role in ensuring more meaningful activity assessment.