Advanced randomization using custom scripting

You can use custom scripting to set up custom randomization. An explanation of the script and example script is below.

1. Click on
   • Login »  Surveys »  Edit
2. Set up the survey with all of the questions.
3. In our example, we have 9 questions, numbered Q1 through Q9. Q9 is the last question in the survey. We want to randomize questions Q3 through Q8.
4. Hover over Q2 to bring up the fly-out menu on the ride side of the screen. Click Page Break to add a page break before the randomization script you will be entering.
5. Click the Add Question button just above Q3.
6. Select Custom Script from the Advanced Question Types.
7. Enter the Randomization script as shown below. The first example is basic randomization. The second example includes script for showing a subset of questions from a set of questions to be randomized (such as showing only 3 of a set of 6 questions randomly). The third example includes script for block randomization.
8. Check the boxes for Logic Includes Branching and Enable Auto-submit. Note: if you do not enable auto-submit, respondents will see a blank page where the custom script question appears. By enabling auto-submit, this question will automatically move forward, reducing confusion for the respondent.
9. Click Save.
10. Create Default Branching logic for each question in the randomization group to branch to a block termination question. In this example, the last question in the survey is the branch termination question, Q9. In any scenario, the question immediately following the group of questions to be randomized should be the block termination question.

#set($ary = ["Q3", "Q4", "Q5", "Q6","Q7","Q8"])
#set($ary = $survey.randomizeList($ary))

#foreach( $val in $ary)
 $survey.branchTo("$val")
#end

The script for showing N out of M question randomly is shown below:

#set($ary = ["Q3", "Q4", "Q5", "Q6","Q7","Q8"])
#set($ary = $survey.randomizeList($ary, 3))

#foreach( $val in $ary)
 $survey.branchTo("$val")
#end

Block randomization allows us to group questions together and then randomly display the groups of questions to the respondent. In our example, we want to split the 6 questions into groups of 2 questions. Respondent A might see the groups in this order: block 3, block 1, block 2; Respondent B might see the groups in this order: block 1, block 3, block 2; etc.

The same type of logic is used for randomizing entire blocks of questions. We will split up the 6 questions into 3 blocks of 2 questions each (block 1 = Q3 and Q4; block 2 = Q5 and Q6; block 3 = Q7 and Q8). To set this up in the script, we will only add the first question from each block to the script. We then need to go into the survey and apply Default Branching for the last question of each block (in this example, Q4, Q6, and Q8) to the block termination question (in our example, Q9). Note: just as in the previous examples, branching for each answer does not need to be set, only the default branching option needs to be set for this to work.

#set($ary = ["Q3", "Q5", "Q7"])
#set($ary = $survey.randomizeList($ary))

#foreach( $val in $ary)
 $survey.branchTo("$val")
#end