“…Theory only provides constraints. Cultural–historical researchers might study eye tracking (Korneev, Matveeva, & Akhutina, ) or skin conductance level (Toomela, Nõmm, Kõnnussaar, & Tammik, ) but purpose of these investigations remains the broader, dynamic development of higher psychological function. As noted by Veresov () “theoretical concepts are not ‘toys’ to play with by changing their contents whatever you like, they are not words with different meanings, they are heavy and powerful tools with definite and strong theoretical content.” If, as has been the case for PIR, the experiment or concept is confused with a method moving toward (not from) theory, there is no progress.…”