Investigation 3-2
Cause

Synopsis

Students explore the first of several explanations for finding an association: causation.  Students envision how data would be distributed in a 2x2 table for the known causal association between cigarette smoking and lung cancer.  Given that there are people who have smoked and not developed lung cancer (cell b) and there are people who have never smoked and developed lung cancer (cell c), students begin to appreciate what epidemiologists mean when they say that an exposure and an outcome are causally associated.

Investigation Preparation Checklist

Check alignment with standards.

National or State file

Review Epidemiology Background for Module 3.

Word or PDF file

Review teacher's notes and slides:  [en espaņol:]

Copy Investigation 3-2: Epi Log Worksheet for each student.  [en espaņol:]

Word or PDF file

Estimated Time / Time Management

Approximately one class period.

Look For Students To:

	Accurately describe how people are distributed in the four cells of a 2x2 table.
	Explain why one would expect people to be in cells a and d of a 2x2 table if an exposure causes an outcome.
	Explain how there can be people in cell b of a 2x2 table and the exposure can still be the cause of an outcome.
	Explain how there can be people in cell c of a 2x2 table and the exposure can still be the cause of an outcome.
	Appreciate how an outcome can have multiple causes.