Heads up: teens and drug abuseunderstanding the statistics

Introduction: 2005 Monitoring the Future Survey

* One of scientists’ main tools for understanding drug-abuse trends among teens is the annual Monitoring the Future survey. In this survey, approximately 50,000 8th-, 10th-, and 12th-grade students in public and private schools across the country answer questions that provide information about teen drug-abuse behaviors and attitudes. The Monitoring the Future survey has been done essentially the same way for more than 30 years, so scientists trust the trends that the data reveal.

* Students participating in the survey fill out questionnaires in school. (All answers are kept confidential.) Scientists then tally and analyze the answers. They compare the current year’s results with those from previous years to see how drug abuse among teens is changing. Armed with these results, scientists can target research and drug abuse prevention efforts in areas that most need them.

* Scientists must take precautions when interpreting the Monitoring the Future results. For example, an increase in the percentage of students saying they’ve used a particular drug doesn’t necessarily mean use of that drug is on the rise. The rise has to be larger than the margin of error, which is an estimate of how a survey would vary if it were taken multiple times using a different group of people each time. Statisticians (mathematicians who study statistics) have devised formulas to determine the margin of error and whether a result is or isn’t statistically significant, meaning it didn’t happen by pure chance. The formulas take into account sample size (number of people surveyed), the number of possible answers, and the number of people giving each answer. Scientists use the formulas to help them analyze data from surveys such as Monitoring the Future.

Interpreting the Data: Findings From the 2005 Monitoring the Future Survey

Now it’s your turn to analyze and interpret statistics from the 2005 Monitoring the Future survey. The two bar graphs below chart 12th-graders’ use of two drugs with very ‘harmful health consequences: ecstasy and methamphetamine.

Percentage of 12th-grade students saying they used ecstasy at least once in 12 months leading up to the survey

Ecstasy (MDMA): A human-made drug chemically similar to both stimulants and hallucinogens. Research in animals indicates it can damage the brain. In high doses, it can lead to organ damage, including heart failure, and to rare but potentially lethal hyperthermia.

1999 5.6

2000 8.2

2001 9.2

2002 7.4

2003 4.5

2004 4.0

2005 3.0

Note: Table made from bar graph.

Percentage of 12th-grade students saying they used methamphetamine at least once in 12 months leading up to the survey

Methamphetamine: A stimulant with high potential for addiction. Abuse also can lead to psychotic behaviors and stroke.

1999 4.7

2000 4.3

2001 3.9

2002 3.6

2003 3.2

2004 3.4

2005 2.5

Note: Table made from bar graph.

You’re the Scientist

Write your answers on the back of this page.

1. How did ecstasy abuse among 12th-graders change between 1999 and 2005? When did it rise? When did it fall?

2. How did methamphetamine abuse among 12th-graders change between 1999 and 2005? What word best describes the overall trend?

3. What is the main difference between the ecstasy graph and the methamphetamine graph? (Don’t look at the numbers; look at the general trends shown in the graphs.)

4. The Monitoring the Future survey has found a general decrease in drug abuse among teens since the late 1990s. Did ecstasy and methamphetamine follow this trend?

GRAPH EXERCISE > PAGE TE 4

1. [d] 18,000

2. 1990; 1992

3. [b] 19,000

4. [d] 55%

5. [c] 22,000

6. [d] 44,000

7. Answers will vary.

Lesson 2 Head Up: Understanding Drug-Abuse Statistics

OBJECTIVE

To help students develop an understanding of statistics, find out how scientists collect and use statistics, and use their knowledge to interpret data from the 2005 Monitoring the Future survey (www.monitoringthefuture.org), an annual study of the behaviors, attitudes, and values of teens in America.

NATIONAL SCIENCE EDUCATION STANDARDS

Science as Inquiry; Science in Personal and Social Perspective

LESSON STRATEGY

Introducing the Topic

* Explain to students that statistics is a branch of math dedicated to answering questions by using numbers. Scientists use statistical methods to collect, analyze, and draw conclusions from data. Have students think of ways in which statistics are used to help people understand the world. (Examples may include baseball statistics and student-performance analyses, such as class rank.)

* Tell students that many types of scientists use statistics. One of the most common statistical tools is the survey or poll. In a survey to track drug use among teens, for example, a scientist might ask survey participants .whether they have used a particular drug in the past 12 months. Scientists analyze the results to determine facts about drug use among teens. Have students recall surveys they have heard about lately. What do they think was the purpose of those surveys?

* Explain to students that, in general, the larger the number of people surveyed, the more accurate the survey results will be. Statisticians (mathematicians who study statistics) call the number of people surveyed the sample size. If you ask 10 teens the question, “Do you consider drug abuse to be dangerous?” you will not get a reliable snapshot of how teens nationwide feel about the dangers of drugs. But if you have a sample size of 50,000 teens from all 50 states, you are more likely to get an accurate picture.

* Hand out Reproducible 2. Tell students that they are about to examine and analyze parts of a real statistical study that provides facts about teen drug use.

* Wrap up the lesson by discussing the following questions: Why do scientists collect statistics? How do statistics help in the battle against drug abuse? Were you surprised by any of the data you examined in the reproducible? Why? What type of questions would you include in a Monitoring the Future-style survey in your school?

For more information about the Monitoring the Future study, refer” students to www.monitoringthe.future.org.

ANSWERS TO “YOU’RE THE SCIENTIST” QUESTIONS:

1. Rose sharply from 1999 to 2001; began to decline after 2001.2. Fell from 1999 to 2003. (Small rise in 2004 was not statistically significant.) Fell further between 2004 and 2005. Word: Decline. 3. Methamphetamine abuse showed steady decline; ecstasy abuse rose, then fell. 4. Ecstasy did after an initial increase and methamphetamine followed the trend.

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