Further Research

I would like to explore how often teenagers use drugs. With my data as well as Nagin's, it is difficult to make an informed conclusion without knowing how often the majority of teenage-drug-users use said drugs. An additional survey with further questions such as "How often do you use drugs?", etc. would prove to be very useful. It may also help to seek a source that has already investigated this exact question, although it may be better to discover the answer on my own so it could be used with the other two questions that have been answered.