There are certainly complex variants of regression that could blow up someone’s brain like that poor guy in the horror film Scanners, but the fundamentals are not that taxing on the mind. …………As I explain in more detail in a post from an earlier mistutorial series, A Rickety Stairway to SQL Server Data Mining, Algorithm 2: Linear Regression, regression in its simplest form is just the graph of a line that depicts how much one variable increases or decreases as another changes in value. Once again, don’t be intimidated by the big words though, because regression is really a very simple idea that every college freshman has been exposed to at some point. Recall that in regression, we’re trying to learn something about the relationships between one or more variables, whereas in the case of probability distributions, we’re normally talking about univariate cases, so we’re really trying to learn something about the internal structure of a single variable (or in our case, a database column).
![mssql weighted standard deviation mssql weighted standard deviation](https://www.mssqltips.com/tipimages2/3015_StndDevExcelPivot.jpg)
While researching the topic, I found out that the term “goodness-of-fit” is also used to describe how much confidence we can assign to a particular regression line. Don’t let the long syllables (or the alliteration practice in the title) fool you, because the underlying concept really isn’t all that hard all these statistical tests tells us is whether the distinct counts of our data points approximate shapes like the famous bell curve, i.e.
#Mssql weighted standard deviation series#
…………Throughout most of this series of amateur self-tutorials, the main topic has been and will continue to be in using SQL Server to perform goodness-of-testing on probability distributions.