Dear Professor, I got confused after reading the threads. I want to clarify again about the input of the best_predictor script: I understood that when: ./cantril_data_cleaning file1 file2 file3 --> The result will be sent to stdout. But for the best_predictor script, you said that "the input to best_predictor will be a TSV file" so it means that for the cantril_data_cleaning, we will send the output both to stdout and a TSV file and then that TSV file is used as the input for best_predictor. Is that correct? For example: ./cantril_data_cleaning file1 file2 file3 . Besides printing to the stdout, it will also print the output to another file like sample1.tsv --> Then we will: ./best_predictor sample1.tsv to report to stdout mean correlation ... like the sample Thank you so much for your clarification!