Describe the key steps you would take to evaluate the cost-effectiveness of two different tactics you are considering influencing the behavior of young adults and therefore to reduce the use of drugs and alcohol consumption in this age group (for example, a mass media campaign targeted to consumer media and college newspapers and publications versus a peer-to-peer series of interactive workshops at local colleges and universities). Focus only on cost-effectiveness parameters (for example, financial cost, human resources, time), and assume that key groups and stakeholders have already discussed and validated both tactics in terms of audience suitability, needs, preferences, and cultural relevance.