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Why Did Visitors at Magic Mountain Get Sick? Last week, 36 people at Magic Mountain were rushed to the hospital due to stomach cramps, fever, and uncontrollable vomiting. You are a forensic pathologist who must figure out what made them sick. Thinking Like a Scientist: Observation
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Why Did Visitors at Magic Mountain Get Sick? Last week, 36 people at Magic Mountain were rushed to the hospital due to stomach cramps, fever, and uncontrollable vomiting. You are a forensic pathologist who must figure out what made them sick.
Thinking Like a Scientist: Observation Scientific thinking begins with observation, the process of gathering information in a careful, orderly way.
Thinking Like a Scientist: Collecting Information What type of questions could we ask that would help us gather more information about the mystery illness? • Did the sick people ride any roller coasters? • How many roller coasters did they ride? • Did the sick people drink alcohol that day? • How much alcohol did they drink? • What kind of food did the sick people eat? • How much food did they eat?
Thinking Like a Scientist: Collecting Information • Did the sick people ride any roller coasters? Most of them rode Full Throttle • How many roller coasters did they ride? 4-6 roller coasters each • Did the sick people drink alcohol that day? Most of them drank Coronas • How much alcohol did they drink? 0-6 beers • What kind of food did the sick people eat? They all ate BBQ ribs at the Yosemite Sam Grill • How much food did they eat? They all ate 16-20 oz of pork ribs
Thinking Like a Scientist: Collecting Information • Did the sick people ride any roller coasters? Most of them rode Full Throttle • How many roller coasters did they ride? 4-6 roller coasters each • Did the sick people drink alcohol that day? Most of them drank Coronas • How much alcohol did they drink? 0-6 beers • What kind of food did the sick people eat? They all ate BBQ ribs at the Yosemite Sam Grill • How much food did they eat? They all ate 16-20 oz of pork ribs Quantity Quantitative observations can be counted or measured.
Thinking Like a Scientist: Collecting Information • Did the sick people ride any roller coasters? Most of them rode Full Throttle • How many roller coasters did they ride? 4-6 roller coasters each • Did the sick people drink alcohol that day? Most of them drank Coronas • How much alcohol did they drink? 0-6 beers • What kind of food did the sick people eat? They all ate BBQ ribs at the Yosemite Sam Grill • How much food did they eat? They all ate 16-20 oz of pork ribs Quality Qualitative observations cannot be counted or measured.
Thinking Like a Scientist: Inference • Did the sick people ride any roller coasters? Most of them rode Full Throttle • How many roller coasters did they ride? 4-6 roller coasters each • Did the sick people drink alcohol that day? Most of them drank Coronas • How much alcohol did they drink? 0-6 beers • What kind of food did the sick people eat? They all ate BBQ ribs at the Yosemite Sam Grill • How much food did they eat? They all ate 16-20 oz of pork ribs Based on the observations, we can make an inference (logical guess): the ribs had something to do with the mystery illness.
Thinking Like a Scientist: Hypothesis Based on the inference, we can form a hypothesis (proposed explanation): the cause of the sickness experienced by the 36 people was food poisoning.
Testing the hypothesis: Experiment To see if our hypothesis is correct, we conduct an experiment. We analyze the pork meat that was used to make the ribs, checking for dangerous chemicals or microorganisms.
Results of the Experiment Analysis of the pork shows traces of a parasitic worm, Trichinella. It is common, and is normally killed by cooking.
Our hypothesis is supported! Can we now consider it a theory?
Hypothesis vs. Theory A hypothesis does not become a theory until it has been tested many, many times under different conditions. Our hypothesis is supported, but it is not yet a theory. The meat company also supplies pork to Universal Studios and Disneyland. Did anyone there get sick? Does their meat test positive for trichinella?
Revising the Hypothesis If the hypothesis is not supported (or if new information emerges), we might have to revise (change) our hypothesis. We learn that 20 other people at Magic Mountain that day ate chorizo made from the same pork. They didn’t get sick! Maybe it was the barbecue sauce?
Revising the Hypothesis A hypothesis must be testable; otherwise, it is not useful. Sadly, we find out that all of the BBQ sauce used that day has been thrown out. We cannot test it to see if it was tainted!
Summary • Observations lead inference • Inference leads to hypothesis • Hypothesis may be supported, but it is not yet a theory • A theory is well-supported – it has been tested many times