In this set of material, the reading passage introduces the concept of correlation in statistics. On the other hand, the listening section informs the potential danger of correlation in seveal ways.
According to the reading passage, correlation studies reveal a relaitonship between the two events. There are two types of correlation. For example, if a student studies a certain amount of time and it leads to better scores of a test, it is possible that the two(the amount of studying time and test scores) are in the positive correlation. On the other hand, if the student spends more time in watching TV, and the student gets a lower score in the test, we can say the two are in a negative correlation.
However, according to the listening, the correlation is always easy to find out. In particular, if you investigate further, it is difficult to differentiate between a correlation and a causation. Even when there exists correlation between two events, it is dangerous to posit that there is a caustive relationship just because of the correlation of the two. Another hazerdous point of correlation studies is difficulty from the third variable in the study. For example, when there is positive correlation between ice cream sales and boating activities. it is possible to say that there is a correlation between the two events. However, given the fact that boating actitives usually take place in summenr and ice cream sales increase in summer, it is a bit far-fetched to postulate that the two events is in a caustive relation because ice cream sales usually is in high in summer. Likewise, if a researcher does not control the thrid variable, it is hard to find any causative relationship between the two events. Nontheless, as is seen in smoking and cancer correlative relationship, correlation can serve as a putative causation between the two events. |