The third category involved specific information on electrochemistry: the Professor asked the students, "Why do we heat? To remove the water, otherwise it forms hydrogen with the electrolyte under electrochemical operation". The instructor said: Using Nvivo 12, we were able to perform a cluster analysis to calculate an encoding similarity index between each training session using similarity measures known as Pearson correlation (Table ). From this similarity analysis, we can say that the verbatims related to order errors (known as "operational errors") are strongly correlated with the verbatims related to the lack of visibility of the external environment (r = 0.71).