Batch 2 - Class 265 - Introduction to Data Science II

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Preclass Exercise:

Kids should complete their own exercise, and figure out the predictor using training data. Then test their predictor against the test data.

Attendance: Raghav, Ayush, Aneesh, Shikhar, Rohan, Mihir, Vivaan, Aarkin, SiddhantJ, Vansh, Harshiet, Rehaan, Kabir, Siddharth, Angad, Advay

Class Notes: (Repeat from class 60)

What is different between the group in figure 1 and the group in figure 2?
What is the responding variable in the above experiment?
Name two variables that would have to be held constant in this experiment and explain why?
Write a hypothesis for the above experiment.
Which figure represents the control in the above experiment? Why?
In graphing this problem what would be on the “X” axis?

Ask kids what kind of experiment should they design so that effectiveness of a drug can be tested?

Notion of Control Set - note that pure observational studies may not require control set
"Placebo" in medical terms

Example: An experiment studies the effects of an experimental drug on the number of offspring a mother mouse has. 10 female mice are given the drug and then impregnated. The number of mice in their litters is compared to the litters of mice that did not take the drug. Look at the Excel table, and draw your conclusion.

Problem 2: Wolf and Deer (Excel sheet) - In 1970 the deer population of an island forest reserve about 518 square kilometers in size was about 2000 animals. Although the island had excellent vegetation for feeding, the food supply obviously had limits. Thus the forest management personnel feared that overgrazing might lead to mass starvation. Since the area was too remote for hunters, the wildlife service decided to bring in natural predators to control the deer population. It was hoped that natural predation would keep the deer population from becoming too large and also increase the deer quality (or health), as predators often eliminate the weaker members of the herd. In 1971, ten wolves were flown into the island.

The results of this program are shown in the following table. The Population Change is the number of deer born minus the number of deer that died during that year. Fill out the last column for each year

On the Excel sheet, fill in the last column
Draw a chart to plot Deer and Wolf population
Explain what happened to wolf and deer population between 1971 and 1980
What would have happened if there were no wolfs introduced
What was the hypothesis?
Do you buy into the "balance of nature" hypothesis? Why are deer better off to die off predators than by starvation? Some people claim that the weakest deer die from wolves, while the youngest may die from starvation - how would you prove such a hypothesis?
Would the deer on the island be better off or worse off with and without the wolves?

Homework:

Pick up a problem of your interest, and search the web to find out data sources related to that. Analyze those data sources to validate or invalidate some common hypotheses.

References: