How to randomly select 6 sets of trials and randomize them afterwards. (case 27392)

[Researcher321]

For your file named Exp 2.cv, insert a row after trial 48 in the block (e.g., right after row 50). Use a value of 0 in the wgr cell of this new row. This will make DirectRT present only 48 trials randomly selected from the ones in your .csv input file with the same number in the wgr cells.

To ensure that only 48 trials are presented, use the skip feature of DirectRT in this same row (see http://www.empirisoft.com/directrt/h...t_skipping.htm). Skip to the trial that follows the last of the possible 256 trials (i.e., row 259 of the Exp 2.csv file). I would also recommend using unique numbers in the trial cell of all the rows of your .csv input file to avoid possible confusion.

Thank you for the response, this was incredibly useful. However, is it possible to randomly select a number of blocks of trials and then in essence combine them into one big block of trials to randomize them once more?

[jason_reed]

I'm glad that this has been helpful. In regards to your last response, is it necessary to randomize twice? Randomization of elements two times does not make the elements "more random" after a first round of randomization.