Question: Im designing a long form on tablet. The form is made up of 5 case studies and 8 questions per case study so 40 questions.

The form is linear but users can choose to jump between sections (i.e. you dont have to fill in each question to get to the next)

My plan is to use LHN for case studies but to display each of the 8 questions on the page. My question is should i display questions all open (they can just scroll to see it) or do i show a collapse view as per image so users get an understanding of the form. 

The form is an interview form and users (interviews) will be reusing the same form for each interview[![enter image description here](https://i.stack.imgur.com/l0Hgv.png)](https://i.stack.imgur.com/l0Hgv.png)

Answer: 
The idea to collapse the dragged item and represent it somehow in a small form while dragging is good. However what about the other large items, possibly adjacent to the dragged item?

A different approach is to offer explicit "reorder" functionality, then collapse all items to their small unified form, before allowing to drag.

Going with your idea -- since the items can be taller than the screen, I assume the list can scroll? You need to provide a way to pass the larger thems (or to reach a target below the fold). Implementing it well is not simple.

* You must scroll the list when dragging and the cursor is close to the
edges. The speed of scrolling should be varied according to the
distance from the edge (closer = higher).
* You need to have a precise animation to collapse items, move them, move other items when collapsing or dragging and allowing a target space, etc. It all should feel natural.
* Lastly, you need to ask if your users will assume they can drag items in such a list (may not be a standard/familiar function). A way to increase affordance is to have drag grip icon on each item -- similar to the button you mentioned I think, but maybe more elegant.
When the current item is too tall, maybe allowing the users to see a portion of "other content" will help them to understand that there is some space where they can drag&drop the current item.

Also, perhaps, allowing the screen to auto-scroll when the users are dragging the item nearby the screen edges will be a good interaction?

Have a look at the mobile view of `todoist` or similar list-heavy apps, maybe they have sorted this issue in a smart way that may inspire you or put you in the right direction :)