Lab 1 White Squirrel Example: Hypothesis Development & Experimental Design
Hypothesis Creation
Observation + question: I seem to see a bunch of white squirrels on campus. I wonder if there are more here than in other areas?
Hypothesis Creation
Observation + question: I seem to see a bunch of white squirrels on campus. I wonder if there are more here than in other areas?
- Research to find potential mechanism: This article says it is because white squirrels (in particular) are being fed. Is that why?
- Incomplete Hypothesis: There are more white squirrels here than in other places because they are being fed.
- Correct Hypothesis: White squirrel (S. carolinensis) population abundance at WKU is greater than in other similar areas, like EKU, because they are being fed.
- Null Hypothesis: There is no difference in white squirrel abundance at WKU vs. EKU.
- Prediction: If I can compare the density of white squirrels on the WKU campus to that of EKU, there would be significantly more on the WKU campus.
Experimental Design
- Dependent variable: The number of white squirrels
- Independent variable: Location (WKU vs. EKU)
- Confounding variables: Days spent counting white squirrels, season and weather of sampling days, sample scheme, sampling effort, etc.
- Assumptions: The forgage (e.g., nuts), trees, and predator populations would be roughly similar. We should also sample these variables, just to be certain. Otherwise we could not rule them out as reasons more white squirrels are located on WKU's campus.
STOP HERE FOR LAB 1
Lab 2 White Squirrel Example (continued): Analysis
Analysis. On 10 similar days, 10 students systematically searched each campus trying to spot at least one white squirrel (we won't get into the details of population sampling right now). They marked if a sighting was made by anyone on each sample run (see data table).
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Extend your knowledgeThis is a real citizen science project logging white squirrel sightings across the US!. Read more about it HERE.
If you need more help with this concept or if you are just curious to know more!
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