Reply To: Randomization by feature and by item

PennController for IBEX Forums Support Randomization by feature and by item Reply To: Randomization by feature and by item

#9616
Jeremy
Keymaster

Hi,

The columns are not randomized: the features array is randomized, which contains predicates over labels of trials; in effect, it is the order in which the trials are inserted in the sequence that is randomized, not the table or its columns, and not the way the trials are created more generally

If you want to detect a change in feature upon runtime, you can use a global Var element to remember the value of the Feature column from the trial that was run before the current one, and compare the value of that Var element with the current value of row.Feature: if they are different, it means the current trial is starting a new feature block:

newTrial( row.Feature + "-" + row.Item ,
  newText("instruct_exerc", "Bitte bewerten Sie, ob beide Tiere gleich gut Verursacher oder Empfänger der Handlung sein können.")
    .css({'font-family': "helvetica"})
    .center()
    .print()
    ,
  newVar("feature")
    .global().test.is( row.Feature ).failure(
      newText("feature_change", "Attention: New Feature ")
        .cssContainer({"margin-top":"2em", "margin-bottom":"2em", 'font-family': "helvetica"})
        .css("font-size", "1.2em").color("Red").bold().center()
        .print()
    )
    .set( row.Feature )
  ,

Jeremy