This is an attempt to discuss various approaches developed in experime
ntal design when constraints are imposed. These constraints may be on
the total cost of the experiment, the location of the supporting point
, the value of auxiliary objective functions, and so on. The basic ide
a of the paper is that all corresponding optimization problems can be
imbedded in the convex theory of experimental design. Part 1 is concer
ned with the properties of optimal designs, while Part 2 is devoted ma
inly to numerical methods. We have tried to avoid details, emphasizing
ideas rather than technicalities. This is not intended as a literatur
e review. The authors subjectively surely left many excellent papers b
ehind.