i have 10 3 min long movie clips. i would like to show subsets of each movie (ie first 10 seconds, first 30 seconds, last 10 seconds, last 30 seconds, complete clip) in a random order, intermixed among movie clips. after each clip ends the subjects make a rating (Y/N). i woud like to control how many 10 second / 30 seconds/ etc clips there are, but have direct RT display them in a random order. Since every subject is not going to see the complete set of movie clips and time combinations, i can't use the within block randomization. i need a way for direct RT to pull the list of movies and times from a file, and then combine them to make sure the same clip isn't showed in the same time interval twice. thanks!