Randomization problem with directRT

[I][edited by moderator][/I]

I have a question about the random functionality of DirectRT. Participants see 16 pictures and have to rate each picture on 4 different questions. They also hear 16 speakers and have to rate each speaker on 4 different questions.

My problem is that I want to randomize the two blocks so that some participants first rate pictures and then speakers or the other way around. The problem with that is that then I can’t randomize the presentation of different photos and corresponding questions correctly (i.e., If I assign to all photos wgr 1, and questions 0 than I’ll randomize presentation of photos but not of 4 questions).

Is there a way to randomize questions like this as well as the blocks? If I assign different wgr number to different questions block, than the problem is that directRT takes any question block and not the one that is under the photograph (which is a problem later on to figure out which answer is related to which photo).

I hope you cold understand what my problem is, and that you have a solution for it.

Thank you very much in advance for your help.

I believe I understand. The problem is that you are already using the BGR function to keep your ratings together with your stimuli. So then you can't use BGR to randomize the order of image/audio.

There are a number of ways you could approach this. I think the easiest would be to create two input files--one for images and one for audio and then have MediaLab take care of the administration of the files. Or you could run the two sessions back to back manually using a pre-determined random ordering by subject ID. In the next version, we hope to have the capability to use multiple levels of BGR and WGR randomization for just this very kind of thing.