As a result of a comprehensive research about gross flows and survey sampling, we have been published in Survey Methodology. The paper presents a new methodology for the proper estimation of gross flows when using complex samples.
Reproducibility: our biggest concern as statisticians
What do identify scientists? In a nutshell, if you claim yourself as a scientist, your scientific results must be reproducible and they could be replicated. That’s it.In my consulting work, I’ve had this concern since the very first moment. It would be not surprise anybody that as statistician we concern about reproducibility. However, I’ve noticed … Sigue leyendo Reproducibility: our biggest concern as statisticians
It had to be U – the SVD song
This song reminds me the several hours that I spent in the undergraduate course of matrix algebra for statisticians in UNAL.
Leslie’s Advice on Statistical Design
An old issue of Statistical Science includes an interview with Leslie Kish by Frankel and King. Leslie was the most influential statistician in the field of Survey Sampling and Statistical Design in the past century. I wan to stress out these words of mere wisdom: Now we are at a very important point. How does statistical … Sigue leyendo Leslie’s Advice on Statistical Design
Removing data from Workspace in RStudio (for MAC users)
In order to remove the data saved (maybe by mistake) in your workspace from RStudio, you gotta find the route in the first message that you can see when opening RStudio. For example, in my case I can read the following sentence when opening the software: Workspace loaded from ~/.RData.Then, open the terminal and write the … Sigue leyendo Removing data from Workspace in RStudio (for MAC users)
DEFF is an ex-ante measure
The Design Effect is measure of efficiency defined as the ratio between two sampling variances: $$DEFF=\frac{Var1}{Var2}.$$Before discussing the design effect properties, it is necessary to define what a sampling strategy is. This is a pair composed of an estimator (of a single parameter of interest) and a probability measure (or sample design). In the computation … Sigue leyendo DEFF is an ex-ante measure
Thinking weirdly
Today I was talking with an old acquaintance. This guy is an statistician that thinks different. I don’t know how to describe its way of thinking, but I know how to describe our way of thinking. As Colombian statisticians:As soon as we arrive to the labor market, we begin to think with a little bit … Sigue leyendo Thinking weirdly
LaTeX for statisticians
What do successful statisticians do in real life? I think that success relies in effective communication. All of the time, we are in broadcast mode: our ideas, results and analysis yield to decision making and it is up to us to find compelling ways to seed our beliefs in those statistical analyses into the mind … Sigue leyendo LaTeX for statisticians
We don’t practice what we preach
In an old issue of CHANCE, you can find an excellent article by Gelman & Loken about ethics and statistics. You should read it and then think about the interplay between your profession and your practice (in teaching and consulting). Here are some ideas taken from the article:We are very serious when it comes to … Sigue leyendo We don’t practice what we preach
Selecting a Real Sample for Electoral Studies
What is the sample size required to achieve a particular margin of error in electoral studies? Professor Leonardo Bautista found that at least 15.000 people should be interviewed, distributed in 6.200 blocks, 80 municipalities and 4 strata. That is a lot of people! — In average, 188 persons per municipality. — Now, do the math. If a single … Sigue leyendo Selecting a Real Sample for Electoral Studies
Regression discontinuity plots with R (using ggplot2)
In public policy evaluation sometimes we use a regression discontinuity analysis in order to estimate the impact of an intervention.Long story short, we suppose that there is a threshold (real value of a design variable) for which we can divide the population of interest into two groups. So, for those individuals that have values higher … Sigue leyendo Regression discontinuity plots with R (using ggplot2)
LaTeX for Statisticians (Our course in USTA)
What do successful statisticians do in real life? I think that success relies in effective communication. All of the time, we are in broadcast mode: our ideas, results and analysis yield to decision making and it is up to us to find compelling ways to seed our beliefs in those statistical analyses into the mind … Sigue leyendo LaTeX for Statisticians (Our course in USTA)
Muestreo, encuestas y estadísticas oficiales 