Monitoring the Future is an annual survey given to 50,000 8th, 10th and 12th graders in the United States to determine drug use trends and patterns, including scales measuring behaviors, attitudes, and values. The survey started in 1975, with 12th graders. It was expanded in 1991 to include 8th and 10th graders as well. To collect longitudinal data, samples of each graduated class are asked to complete follow-up questionnaires via postal mail.
The survey is given anonymously, so while there can be no repercussions for admitting drug use, there is also a questionable level of trust involved. Some students find a sort of rebellion in skewing the results intentionally. Though the same elements of statistical data misrepresentation exist in all surveys, the immaturity levels combined with an exciting "taboo"(many public schools won't allow discussion of obscene topics, such as illicit drug use, and so the ideas of drug taking is given an unwarranted forbidden appeal) should lead one to an even less literal acceptance of the findings compared to studies done on informed adults.