PennController for IBEX › Forums › Support › Randomization with no more than three items of same category in a row › Reply To: Randomization with no more than three items of same category in a row
I have a very similar question to the one posed here, but I cannot seem to make it work unfortunately. So I am creating a rating study with 22 photos and 10 questions. Each photo appears ten times with each question so I have 220 items in total. I also have 4 practice items that appear with five of the questions so another 20 items in the beginning. I am using the pick function in order to add breaks and attention checks in between, as well as randomise the items, but some items come up two or three times in a row, something that I want to avoid – I do not wish to have any duplicates.
I have tried replicating the code you provided above (+ uploaded the .js file to js_includes) but with no success so far.
My sequence looks like this:
practice = randomizeNoMoreThan(startsWith("practice_trials"), 1); critical = randomizeNoMoreThan(startsWith("experimental_trials"), 1); PennController.Sequence("welcome", "demographics", "instruction", "exampleinstruction", pick(practice, 20), "end_practice", pick(critical, 55), "attentionCheck1", pick(critical, 55), "break", pick(critical, 55), "attentionCheck2", pick(critical, 55), "send", "final")
and then within my trials I have this format (VP is the column with the coding of the photos that I do not want to see more than once in a row):
PennController.Template( PennController.GetTable("List_1.csv") .filter("trial_type", "practice") , variable => ["practice_trials_row.VP"
PennController.Template( PennController.GetTable("List_1.csv") .filter("trial_type", "experimental") , variable => ["experimental_trials_row.VP"
Is there a way to fix this? (Link to the experiment: https://korpling.german.hu-berlin.de/ibexexps/tsiapoud/Fotodatenbank_Pretest_List_1/experiment.html)
Thanks in advance!