Should fields be hidden if another field could appear in between?

Question

I'm making a form which will have various yes/no answers. In response to the user's action, the form might display more fields. Some fields will always be displayed.

For example (completely made up questions):

Question 1

• Question: Have you ever been skydiving before?
• Display condition: N/a

Question 2

• Question: Would you like to have the vertical wind tunnel training first?
• Display condition: (response from 1) == No

Question 3

• Question: Would you like to rent a GoPro for £x?
• Display condition: N/a

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How would this be best displayed? The options I can think of are:

• Display all questions that will always display and show new questions as the display conditions are met. This might mean a question will appear between 1 and 3. I think this might confuse users.
• Display questions 1 at a time, showing new questions as the previous one is answered. I don't like this idea because the user would have no idea how long the form will be.

We use a form building platform that offers little control so it wouldn't be possible to do anything fancy.

Answer 1

It depends what is the amount of condition met hidden questions. If it is less than 25% of all questions, I think that toggling it in between is ok. If it is more I would move to multi step based form. You should always include system status indicator / progress bar there so user knows how far he is. Also it is good to before start of the form indicate approximate time user will need to fill it.

Answer 2

I would add to make sure that the form is client-based and not server-based so that if you are using the hidden additional questions there is no added delay which only adds to the confusion.

Answer 3

I suggest not going the one-at-a-time route for these reasons:

1. Without an indication of how long a task will take, many users will simply abort the task altogether. If the user does not immediately know how many questions there will be they may not even begin, or quit after answering an arbitrary number of questions which they deem "too many".

2. If you show questions one at a time, it introduces a new problem of allowing the user to navigate to previously answered questions, should they wish to change them. Furthermore, each time the question is changed there is a new cognitive load of some part of the screen refreshing.

3. Users like to scan. By only showing one question at a time, you do not allow the user to gather information about the task at hand, which can make the user feel a bit "trapped".

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How you show the conditional questions will likely depend on the dependency structure of the conditional questions.

For a simple case where a conditional question only relies on a single parent, then I suggest displaying that question as a "sub question" of the parent question. Whether or not you hide/show the question is up to you -- is it beneficial to your goals if the user can see the question before the parent is answered?

For a more complex case where a question should only be shown based on some combination of other questions, I would make sure that the question is asked after (further down the page) all of the required questions.