Textbook Topics: The effect of outliers
In Chapter 10 of the Standard textbook, I worked on analysing data, one specific topic in that chapter that fascinated me was the effect of outliers.
The textbook states that an outlier is “a very high or very low score in a data set that is clearly apart from the other scores. It can occur for a variety of reasons and should be investigated. If it was obtained through incorrect measurement, it should be excluded.” I find the definition of an outlier in itself fascinating, especially its emphasis on investigation as I do find it interesting when I see an outlier and I’m always curious as to how and why it is there.
The textbook stated how outliers can affect the measures of central tendency of a data set – The mean (average) is the most affected by outliers as its value depends on every score, the median can be affected but not by much, and the mode is not affected at all.
The most fascinating part of this topic within the textbook is the real-life example that was provided to illustrate why outliers shouldn’t be ignored – The Challenger space shuttle disaster.