Problem 1. (T/F/U. Justify your answer.) The randomization in an experiment solves

all possible selection bias problems.

Problem 2. (T/F/U. Justify your answer.) In the context of scalability, the 'voltage effect' denotes the specific situation where the benefits of a program decreases when the program is scaled up. Thus, the policymaker who wants the highest benefit-cost ratio must focus in keeping high fidelity during the scaling process.