# Opinions on Standard deviation

Here you have a list of opinions about Standard deviation and you can also give us your opinion about it.
You will see other people's opinions about Standard deviation and you will find out what the others say about it.
Also, you will see opinions about other terms. Do not forget to leave your opinion about this topic and others related.    In statistics, the standard deviation (SD) (represented by the Greek letter sigma, σ) is a measure that is used to quantify the amount of variation or dispersion of a set of data values. A standard deviation close to 0 indicates that the data points tend to be very close to the mean (also called the expected value) of the set, while a high standard deviation indicates that the data points are spread out over a wider range of values.

The standard deviation of a random variable, statistical population, data set, or probability distribution is the square root of its variance. It is algebraically simpler, though in practice less robust, than the average absolute deviation. A useful property of the standard deviation is that, unlike the variance, it is expressed in the same units as the data. Note, however, that for measurements with percentage as the unit, the standard deviation will have percentage points as the unit. There are also other measures of deviation from the norm, including mean absolute deviation, which provide different mathematical properties from standard deviation.

In addition to expressing the variability of a population, the standard deviation is commonly used to measure confidence in statistical conclusions. For example, the margin of error in polling data is determined by calculating the expected standard deviation in the results if the same poll were to be conducted multiple times. The reported margin of error is typically about twice the standard deviation—the half-width of a 95 percent confidence interval. In science, researchers commonly report the standard deviation of experimental data, and only effects that fall much farther than two standard deviations away from what would have been expected are considered statistically significant—normal random error or variation in the measurements is in this way distinguished from causal variation. The standard deviation is also important in finance, where the standard deviation on the rate of return on an investment is a measure of the volatility of the investment.

When only a sample of data from a population is available, the term standard deviation of the sample or sample standard deviation can refer to either the above-mentioned quantity as applied to those data or to a modified quantity that is a better estimate of the population standard deviation (the standard deviation of the entire population).

In the image below, you can see a graph with the evolution of the times that people look for Standard deviation. And below it, you can see how many pieces of news have been created about Standard deviation in the last years.
Thanks to this graph, we can see the interest Standard deviation has and the evolution of its popularity.

# What do you think of Standard deviation?

You can leave your opinion about Standard deviation here as well as read the comments and opinions from other people about the topic.
It's important that all of us leave our opinions about Standard deviation to have a better knowledge about it: