I have a general list of 1800 participants which I invite to my studies. I had 180 participants in an old study for which I have to get new data for a revise now. So I would like to invite the 1800 participants for the new experiment, but without the 180 subjects who already completed the study. Is there an easy way to eliminate the 180 subjects from the general list of participants? Of course I could do it one by one, but I am looking for something that works more conveniently. Thank you !
Of course I can eliminate each adress one by one in Excel. But can I also eliminate the 180 subjects in one step? I have two excel files one with the 1800 partiicpants the other with the 180 I want to eliminate. What would be the next step?