Story 1:

When Erin visited Ukraine, she made two interesting observations. While staying in Ivankivci village, she observed that many people in this village did not clean their frying pans and reused grease that had accumulated over and over again. While volunteering at the Record Keeping Archive of a local hospital, she observed that there was an unusually high incidence of esophageal and pancreatic cancers among citizens of this village.

Questions:

1. Based on Erin's observations, please propose a hypothesis, which would explain the high incidence of esophageal and pancreatic cancers among the citizens in the village in Ukraine.

2. Based on your hypothesis, please make a prediction.

3. What kind of experiment(s) might one need to perform in order to validate your prediction? What experimental model is going to be used?

4. What could be a control for this experiment?

5. Can you propose an alternative hypothesis to explain the high incidence of esophageal and pancreatic cancers among the citizens in the village in Ukraine?

Story 2:

For many years marine biologists were recording sounds made by dolphins and whales. While doing this, the scientists noticed that some sounds made by dolphins are very similar to sounds made by whales, while some sounds are very different. In order to study this phenomenon further, they decided to expose a group of whales to recorded sounds made by the dolphins. The whales were exposed to the dolphin sounds, which were similar to the sounds made by the whales. Later the whales were exposed to the recorded dolphin sounds, which were different than those of the whales. In a separate enclosure, the dolphins were exposed to both types of dolphins' sounds. While doing this, the scientists were recording any changes in the whales' behaviors in response to both types of dolphin sounds.

Questions:

6. What hypothesis lies behind the study described above?

7. What prediction can be made based on this hypothesis?

8. What kind of results would validate this hypothesis?

9. What kind of a control is used in the study described above?

10. If scientists obtained results, which were opposite from what you described in 8, what kind of conclusions should be drawn then?