Can I mark the work as they go?

No, you can only mark the work once the entire assignment is completed (see Section 7.2 of the specification for more detailed information). You cannot mark between tasks. The Student Guide to NEA should be shared with students as they start studying the course. It highlights the support you can give them, including when marking takes place and what feedback you can give.

Refer to the specification about the kind of general feedback that is allowed throughout the completion of tasks to ensure students are working appropriately and accessing all of the criteria available.