What is a limitation of indirect electrochemical measurement techniques?

Indirect electrochemical measurement techniques primarily focus on measuring secondary responses or properties associated with electrochemical reactions rather than directly measuring the electrochemical reactions themselves. This means that while useful, these techniques do not provide direct data about the electrochemical processes occurring at the electrodes.

For example, techniques like impedance spectroscopy measure changes in impedance that can be correlated to electrochemical processes but do not measure current or voltage directly related to the electron transfer during the reaction. As a result, the data derived may require interpretation and cannot straightforwardly inform about the specifics of the actual electrochemical reaction, such as reaction kinetics or mechanisms.

This characteristic of indirect techniques is what makes this option the correct answer, as it encapsulates a key limitation that could influence the choice of measurement method in electrochemical studies.