The text discusses four reasons for evaluating interventions.List and explain three of them.

1.Its scientific nature-Based on the tradition of Lewin,one major reason for evaluation research is to test the theoretical assumptions underlying the intervention.
2.Ethical responsibility-Those responsible for the implementation of programs have an ethical responsibility to determine whether their recipients are receiving the intended benefits and whether they are experiencing any unintended undesirable consequences.The ethical responsibility also extends to a readiness to modify or even discontinue ineffective programs and to improve on programs that have been evaluated as effective.
3.The need for financial accountability-For the sake of the funders of programs,there should be accountability in the sense of convincing continued demonstration of program effectiveness.Moreover,even if a program is found to be effective in accomplishing its goals,the program might be too costly.That is,an effective program might cost too much given the available resources that might instead be used for other purposes,including the implementation of other beneficial yet less expensive programs.
4.The need for program development-This may be viewed as the overriding reason for evaluation research.Programs are evaluated as part of the process of developing the most effective programs possible.