If you have a survey with the conditional questions on the basis of which you display successive blocks of questions, and in them you have collected more answers than it should have been, you are probably wondering how it could have happened. However, such a scenario is possible if the conditional questions are included in the survey in which the respondent can change his answers - and he can do it if you have turned on the "BACK" button and the option to go back to already completed questions.

It is best to use an example in this case.

As you can see on page 1 we have a choice of car brands and on the following pages we have defined rules for displaying pages based on teh 1st question.

When the respondent chooses, for example, the answer "Suzuki", he will only see the 4th page, in which he will be able to select the answer to question 4.

And what if the respondent made a mistake and the Suzuki brand was wrong and he wants to evaluate another brand? Thanks to the BACK button in the survey the respondents will be able to go to page 1 and change their answer.

The above mentioned change, unfortunately, may have consequences in the form of collecting more data. When the respondent leaves his answer for the 4th question, where he rated the OPEL brand on the scale, and then returns and changes the answer in the 1st question and will evaluate a different brand, the database will provide answers to question 3 and question 4. As a result, in a single response it will look like this: