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DETECTIVES IN THE CLASSROOM  

Investigation 33

Check alignment with standards. 
Review Epidemiology Background for Module 3. 
Review teacher's notes and slides: [en espaņol:] 
Copy Investigation 33: Epi Log Worksheet for each student. [en espaņol:] 
Prepare a deck of 100 cards with 25 labeled with an a, b, c, and d for each Epi Team. 
Get 1 paper bag for each Epi Team. 
Approximately one class period. Time can be managed by increasing or decreasing the number of 2X2 rate and risk calculations or cell identifications.
Explain how picking 20 of 100 cards is analogous to selecting a sample from a population. 

Explain how the relative risks calculated for each sample of 20 cards is analogous to finding an association by chance. 

Explain how sample size affects the accuracy of a relative risk. 

Consider the possibility of finding an association due to chance. 