You can actually hide or show questions based on the value of other questions.
Conditionnal display allows you to build complex forms, ideal for market research for example.
jform has a really easy Conditionnal Framework. Example: return new field('question_name').equal('no')
will display the current question if the question question_name has the value no. Look at the code of this page to see how easy it is!
Submit the form to see the output.
The source will display here.