This How-To will explain what is the impact of using the ‘Back’ button in interviews.
Let’s say that we have a survey with 3 questions.
The first question has a jump rule saying:
“If my answer is 1, I need to jump to question 3″.
Now, think of a scenario where the respondent, has answered question 1 with answer 2, proceeding to question 2 and answering it – Then from question 3, using the back button returning back to question 1 and changing its answer to answer 1, causing it to jump over question 2 directly to question 3.
This is problematic, how would the system know if Question 2 was answered or not? Is relevant or not? Should it show as a missing value or not?
As although it was answered, it was also skipped.
Therefore, in such scenarios the system handles it with a value called ‘Null Response’.
If I view the result through the operations console, I will notice there is no answer for question 2 not as the answer provided before the "back" usage.
Further more, if I export the data, it will be missing.
Basically ‘Null Response’ is a status given to questions that are being skipped, so the system will know how to handle them when exporting.
This impact of the back button, might cause sometimes, a lot of inconvenience if mistakenly used by surveyors, causing big amount of data to appear as missing, even though answers were provided.
However, if you double-click on the question in the result window, and in question2 window- click the ‘Internal Data’ button, you would be able to see the real value of this question.
*When question 2 was answered before using the 'back', the provided answer was 2.
In order to fix that and set the answer, if needed, you would need to:
1. Manually change the result to a Read\Write mode such as ‘Requires Approval’ in the operations console
2. take off the ‘Null Response’ check box and update the answer in the text box.
If you wish to hide the ‘Back’ button and not to allow surveyors to go back, you can do it through the "survey properties" tab, in the "display" section:
*Advanced note: Instead of checking all questions, you can view the interview’s log and see that behavior that caused the Null Responses.
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