Tells which column in the table assigns each row to a given group of participants, i.e. which subset of rows PennController will keep for each group of participants listed in the column.



What does (PennController.) mean?


@AddTable( "test_table" , 
@    "Spelling,Text\n"+
@    "Normal,Hello\n"+
@    "Reversed,olleH\n"+
@    "Normal,World\n"+
@    "Reversed,dlroW"
@    GetTable( "test_table" ) 
$            .setGroupColumn( "Spelling" )
@    ,
@    row => newTrial( "button trial" ,
@        newButton("the button", row.Text )
@            .print()
@            .wait()
@    )
@    .log( "Group" , row.Spelling )
@    .log( "Text"  , row.Text     )
  • Creates a 2x4 table called test_table with column names Spelling and Text (manual creation for purpose of illustration—you would normally upload a CSV file to chunk_includes). Uses the column Spelling from this table to identify which rows go with which groups of participants.

  • Every other time the experiment is run, participants will see trials generated either from the two rows where Spelling is Normal or from the two rows where Spelling is Reversed.

  • The very first line runs a trial incrementing Ibex’s internal counter at the beginning of the experiment, which determines which group is run, so you can cycle through the rows if you re-run the experiment.