W-2 wages: everyone on payroll, including owners who are on payroll. We apply your industry's typical share, so there is no need to pick out research staff.
Supply costs: materials and parts used up while designing, building prototypes, or testing.
Contract research: outside engineers, testing labs, consultants, or developers you paid for technical work. Enter the full amount.
Not sure if something counts? Include it. Sorting out what qualifies is our job, and we do it on the call.