Can all nonpro?t programs and services be evaluated? Think of some types of nonpro?t programs or services that might be very difficult or impossible nonprofits to evaluate. What accounts for the difficulties? How might evaluation design be used to address these difficulties? 15.1 Six reasons why nonpro?ts might collaborate were identi?ed (social responsibility, operational ef?ciency, and so on). Might it be possible for a particular collaboration to advance one of these objectives while detracting from another? In the case of this kind of con?ict, what factors might lead a non pro?t to favor one objective over another?