Hello. I developed an algorithm to detect events in time domain and I want to know the efficiency of the algorithm. The problem is related with the time duration of the data. Each file has data with a time duration of hundreds of minutes and I have dozens of files. Instead of calculate the specificity and the sensitivity of this algorithm for the entire data set, I was thinking to choose random samples. My question is: What is the correct approach to have a valid statistical analysis? Thank you.