I am building an experiment in which I present 40 five sec videos. I am interested in participants’ facial expressions as they watch them, so I am using the 'cam" function. The basic experiment is working fine, including randomizing the stimulus videos, capturing, and storing the participant’s facial expression. In the next phase of the experiment I want to show the captured videos to observer-participants and have them rate the videos. At 40 videos per participant and likely 100 participants, that’s 4000 videos. The problem is the labeling of the output videos and their identification in the Excel output file. Here is an example of the labeling of one file in the Excel file: “C:.….….….…\Synesthesia experiment\data/944557_Synesthesia experiment_2023-09-01_15h38.53.018_cam_recorded\recording_cam_2023-09-01_15h39.19.753.mp4”. The video label then reads “recording_cam_2023-09-01_15h39.19.753.mp4”. This will be a headache to manage in the second phase. Is there a way of changing the default labeling such that the Excel file and the associated video output file will be more transparent; for example, by listing the participant number, the condition of the video the participant watched, and perhaps its serial order in the randomized sequence? Something like P001v1controltrial25. Thanks for any help you can provide.