Linked Questions

192 votes
80 answers

Statistics Jokes

Well, we've got favourite statistics quotes. What about statistics jokes?
562 votes
23 answers

Why square the difference instead of taking the absolute value in standard deviation?

In the definition of standard deviation, why do we have to square the difference from the mean to get the mean (E) and take the square root back at the end? Can't we just simply take the absolute ...
c4il's user avatar
  • 5,875
286 votes
11 answers

How would you explain covariance to someone who understands only the mean?

...assuming that I'm able to augment their knowledge about variance in an intuitive fashion ( Understanding "variance" intuitively ) or by saying: It's the average distance of the data ...
PhD's user avatar
  • 14.8k
124 votes
3 answers

Intuitive explanation of unit root

How would you explain intuitively what is a unit root, in the context of the unit root test? I'm thinking in ways of explaining much like I've founded in this question. The case with unit root is ...
Lucas Reis's user avatar
  • 2,062
38 votes
8 answers

What is a standard deviation?

What is a standard deviation, how is it calculated and what is its use in statistics?
Oren Hizkiya's user avatar
16 votes
3 answers

Conceptual understanding of root mean squared error and mean bias deviation

I would like to gain a conceptual understanding of Root Mean Squared Error (RMSE) and Mean Bias Deviation (MBD). Having calculated these measures for my own comparisons of data, I've often been ...
Nicholas Kinar's user avatar
2 votes
1 answer

What is sigma2 in output of MCMC regression by MCMCregress of MCMCpack package of R

I am using following data and code: ...
rnso's user avatar
  • 10.1k
0 votes
1 answer

How far is my average from the series values?

I'm sure there's a name for this concept, but I can't find it (I'm not familiar with statistical terms): Suppose I have a series of numbers, and an average of those. I'm wondering how correct this ...
BobbyTables's user avatar
2 votes
1 answer

Empirical Implications of Unbiased Estimators

I am familiar with the layperson explanation of an unbiased estimator as follows: if we repeat an experiment under identical conditions many times, the average value of the estimate will be close to ...
Mr Saltine's user avatar
2 votes
1 answer

Intuitive explanation of "invariance"

...assuming that I'm able to augment their knowledge about variance in an intuitive fashion Understanding "variance" intuitively and about covariance How would you explain covariance to ...
Thalassophile's user avatar
1 vote
1 answer

What is the intuition behind the $N$ in the denominator in the definition of variance?

There are many questions and answers on why $n-1$ is used instead of $n$ in sample vs population variance. However, I wonder why the population variance definition even has $n$ in the first place. The ...
z611's user avatar
  • 255