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## How to de-Bias Standard Deviation Estimates

This note is about attempting to remove the bias brought in by using sample standard deviation estimates to estimate an unknown true standard deviation of a population. We establish there is a bias, concentrate on why it is not important to remove it for reasonable sized samples, and (despite that) give a very complete bias management solution.

Posted on Categories Coding, Opinion, Pragmatic Data Science, Statistics, Tutorials

## R Tip: Think in Terms of Values

`R` tip: first organize your tasks in terms of data, values, and desired transformation of values, not initially in terms of concrete functions or code.

I know I write a lot about coding in `R`. But it is in the service of supporting statistics, analysis, predictive analytics, and data science.

`R` without data is like going to the theater to watch the curtain go up and down.

(Adapted from Ben Katchor’s Julius Knipl, Real Estate Photographer: Stories, Little, Brown, and Company, 1996, page 72, “Excursionist Drama 2”.)

Usually you come to `R` to work with data. If you think and plan in terms of data and values (including introducing more data to control processing) you will usually work in much faster, explainable, and maintainable fashion.

Posted on Categories Coding, data science, Opinion, Programming, Statistics, Tutorials13 Comments on Tutorial: Using seplyr to Program Over dplyr

## Tutorial: Using seplyr to Program Over dplyr

`seplyr` is an `R` package that makes it easy to program over `dplyr` `0.7.*`.

To illustrate this we will work an example.

Posted on Categories Coding, Opinion1 Comment on Another R [Non-]Standard Evaluation Idea

## Another R [Non-]Standard Evaluation Idea

Jonathan Carroll had a an interesting `R` language idea: to use `@`-notation to request value substitution in a non-standard evaluation environment (inspired by msyql User-Defined Variables).

He even picked the right image:

Posted on Categories Administrativia, Statistics5 Comments on My recent BARUG talk: Parametric Programming in R with replyr

## My recent BARUG talk: Parametric Programming in R with replyr

I want to share an edited screencast of my rehearsal for my recent San Francisco Bay Area R Users Group talk: