Preview p.22

• A gym teacher has his four classes see how many free throws each student can make out of fifteen attempts. The numbers on your handout represent the number of baskets.

• Complete TASK #1 on the “Frequency Distribution” worksheet.

• (located at the front of the room)

Graph A

Graph B

What are we looking at?

1. When does graph A reach a maximum? When is it at its lowest? What is the general trend?

2. When does graph B reach a maximum? When is it at its lowest? What is the general trend?

3. What information do you think is being shown in each graph?

Ice Cream Sales Over a Year

Crime Rates Over a Year

Correlation

1. Did the crime rate cause the ice cream sales to rise?

2. Did the sale of ice cream cause the crime rate to rise?

3. Is there any link?4. Confounding variables?

Correlation and Causation p.23

• Correlation: A systematic pattern that may emerge when we observe two variables over time. – Does not imply causation because an unmeasured

(confounding) variable may be causing the result.• Causation: There is a direct relationship

between a change in one variable and a change in another variable.

Autism

• Effects approximately 1 to 2 people in every 1000

• Condition effecting neural development causing restrictive, repetitive behavior; autism also affects social behavior and language

Wakefield (1998)

• In Britain, as in many countries, the majority of children are vaccinated against measles, mumps and rubella using a combined vaccine (MMR). A British doctor wrote a report on 12 children who had been vaccinated with the MMR vaccine and were subsequently diagnosed as autistic. The result of this report was that media interest was raised; many anti-MMR stories appeared and there was a significant fall in the number of children given the MMR vaccine.

MMR-don’t die of ignorance

1. Does the fact that children in the report were diagnosed with autism after being given the MMR vaccine prove that the vaccine caused autism?

2. At the time of the report, well over 90% of children had the MMR vaccine. Why should it not be a surprise if some of those children are diagnosed with autism?

3. What kind of survey would have helped identify whether the MMR vaccine caused autism?

1. What happened to MMR vaccination rates?2. What happened to the incidence of the measles?3. Is there a causal link?

The Madsen Study

• Based on data from over half a million children (nearly 100% of the children born in Denmark)

• Over 440,000 had been vaccinated• No greater incidence of autism among

children vaccinated as amongst those not vaccinated.

• Measles kills one in every 3000 people and causes pneumonia in one in 20.

Implications

• Madsen study in Denmark: data from over half a million children (440,000 vaccinated) and there was no greater incidence of autism amongst vaccinated children as amongst those not vaccinated

1. What makes the findings of this study reliable?2. What would you say to someone who still wanted

to “play it safe” by not having their child vaccinated for MMR?

Jenny McCarthy

• How she cured her son’s Autism…?• http://www.youtube.com/watch?v=zdCeRficN

vQ• http://www.youtube.com/watch?v=ErVttd0Q1

Xs

Process p.22

• Consider the following points of view, and respond to them:1. “The doctor who wrote the original report was

right to alert people to his concerns and suggest that more research should be carried out.”

2. “The media got hold of the story and turned it into a huge scare. It's their fault.”

3. “There was never any evidence to prove a link. Thousands of children have caught diseases that could otherwise have been avoided.”