I have a best practice question. I have a form field that has questions with drop downs. Some of the dropdowns answers would make fields appear or disappear. My question is, should all fields be visible when you open the page or should they be loaded by sections depending on what the user chooses in the dropdown menu.
Progressive display appears to be the most sensible here; opening only what's needed based on user response.
However... what you're really creating are "modes" that get experienced based on varying choices. Even though your questions may seem clear enough, users might either a) still not be wholly sure what to choose or b) choose to explore various choices anyway. So, I'm suggesting you make it easy should a user switch paths. (Which they could conceivably also do by accident.) For example, if possible, hold on to answers to sub questions even if they switch paths. This way, they don't lose their work. You only have to send the correct set of answers on form submission, but don't lose prior entries. Let's leave aside any formal studies for a moment and consider your own web experience: How many times have you looked at or used a form and then gone another way, come back, and been annoyed by having to re-enter info?
Progress Bar: Since there's hidden work to be done, if it's more than a few questions, perhaps include a progress bar at the top. This only make sense if the depth is about equal for all question paths. Doing this kind of thing helps set user expectations. It also slightly "gamifies" the system. This method is known to increase completion rates of tasks.
There should be only one section opened in the start which is of greater importance i.e., in terms of usability, or mandatory ones so that the user is not confused on seeing large set of data at a time.
and the second point is about auto hide all other sections on opening a new one(until there is some requirement of previous section on the new ones). if such is the case maintain the same interaction throughout.