Faculty at my institution wish to develop a textbook under a NSF grant.
After it is developed and used to teach a course here, it will be provided to
faculty at other institutions who will "field test" it by using it to teach a
course.  When they were asked and agree to do the field testing, no mention
was made of a fee, yet it's easy to agree now to do something which may or
may not take place a couple of years down the road.

Question: is it customary to provide funds such as honoraria in the budget
for the field testers?  In some respects, the field testers are almost like
evaluation consultants.  Anyone have experience with this? Thanks!