Week 2

-Min, Median, Max

-Symmetry in data

                the distance from Min to Median equals the distance from the Median to Max

                left & right  skewed distributions                                                                                                           QUIZLET

 The link between chocolate (A) and Nobel Prizes (B) and Other factors (Cn) could happen in a number of different ways:

1. A causes B: Chocolate consumption causes Nobel Prizes. We might suggest that substances found in chocolate improve brain activity, thus leading to more research breakthroughs by scientists. In this way, we get the relationship depicted in the graph: countries like Switzerland eat a lot of chocolate and win a lot of Nobel Prizes.

2. B causes A: Nobel Prizes cause chocolate consumption. We might suggest that when people from a particular country win a Nobel Prize, the people in that country celebrate by eating lots of chocolate. We would still see the same relationship depicted in the graph: countries like Switzerland win a lot of Nobel Prizes and eat lots of chocolate.

3. C causes A and B: Some other factor causes both Nobel Prizes and Chocolate consumption. For example, we might notice that Nobel Prizes are more frequent in countries which are quite cold (like Norway and Sweden). It is easier to store and eat chocolate when it is cold than when it is hot, so people living in cold countries might eat more chocolate. It is also easier to concentrate in cold weather than in hot weather, so people living in cold countries might be able to do research better and win more Nobel Prizes. In this way, we still get the same graph: Switzerland is a cold country, and so people eat lots of chocolate and win lots of Nobel Prizes.

Correlation does not imply causation

As you can see, just because two things are linked, this does not mean that one definitely causes the other. Just because two variables are correlated, this does not mean that one causes the other.

As discussed [the information in the article], the link between chocolate and Nobel Prizes is most likely a case where C [another influence causes A and B]. The variable C in this case is wealth, as people in richer countries have more money to spend on luxury foods like chocolate, and also have more money to spend on research. To show this, the authors of this article also did a similar study on sales of luxury cars, and found that they too correlated well with Nobel Prizes.