# 6.5: Bibliography

- Page ID
- 7820

- The word “data” is really a plural, corresponding to the singular “datum.” We will try to remember to use plural forms when we talk about “data,” but there will be no penalty for (purely grammatical) failure to do so.↩
- Sometimes you will see this written instead \(\sum_{i=1}^n x_i\) . Think of the “\(\sum_{i=1}^n{}\)” as a little computer program which with \(i=1\), increases it one step at a time until it gets all the way to \(i=n\), and adds up whatever is to the right. So, for example, \(\sum_{i=1}^3 2i\) would be \((2*1)+(2*2)+(2*3)\), and so has the value \(12\).↩
- no pun intended↩
- This is a very informal definition of an outlier. Below we will have an extremely precise one.↩
- Which might write 5N\(\Sigma\)ary for short.↩
- Although in the 1950s a doctor (who later was found to be in the pay of the tobacco industry) did say that the clear statistical evidence of association between smoking and cancer might be a sign that cancer causes smoking (I know: crazy!). His theory was that people who have lung tissue which is more prone to developing cancer are more likely to start smoking because somehow the smoke makes that particular tissue feel better. Needless to say, this is not the accepted medical view, because lots of evidence goes against it.↩
- It is hard to be certain of the true origins of this phrase. The political scientist Raymond Wolfinger is sometimes given credit – for a version
*without the*“not,” actually. Sometime later, then, it became widespread with the “not.”↩ - There many kinds of infinity in mathematics – in fact, an infinite number of them. The smallest is an infinity that can be counted, like the whole numbers. But then there are many larger infinities, describing sets that are too big even to be counted, like the set of all real numbers.↩
- In fact, in a very precise sense which we will not discuss in this book, the longer you play a game like this, the more you can expect there will be short-term, but very large, wins and losses.↩
- By Dan Kernler - Own work, CC BY-SA 4.0, commons.wikimedia.org/w/index.

php?curid=36506025 .↩ - It dates from the \(5^{th}\) century BCE, and is attributed to Hippocrates of Kos .↩
- When an experimenter tends to look for information which supports their prior ideas, it’s called
**confirmation bias**– MW may have been experiencing a bit of this bias when he mistakenly thought he was average in height for his class.↩