By at April 17 2019 17:53:27
Form length does not directly correlate to complexity. Many assume that making forms shorter makes them easier to complete. Though shorter forms might be cheaper to produce initially, if the reduction in content results in user confusion, the cost of resolving completion errors form fillers make as a consequence can significantly outweigh any initial savings. In general forms do need to be as short as possible, but never at the expense of clarity and usability.
In paper forms the specific sub-questions cannot be hidden from the user when they are not relevant to them - but in interactive forms this is relatively easy to do. Use progressive revealing as much as possible in your form design to shield your users from questions they do not need to see.