As the author of this blog is committed with Colombia national soccer team, here we are again with our predictions (for the sake of tradition) for the Copa América 2015. The opening match is Chile - Ecuador.
The big data fallacy – Misunderstandings in hypothesis testing
WARNING: Keep an open mind while reading! My question: when testing hypothesis, why the critical value is always fixed at 5% level of significance? The rules of thumb in applied statistics are sometimes weird. It has no sense that, for every problem, in every discipline, in every context, in any population, the critical values are … Sigue leyendo The big data fallacy – Misunderstandings in hypothesis testing
Item Response Theory Models in R and JAGS: simulation and bayesian estimation of 1PL models
In my job this kind of models are our daily bread. Item response theory models are used to asses the quality of education, and if you are serious about educational or psychological measurement, this kind of models are mandatory. First of all, IRT models are just that: stochastic models. There is nothing mysterious behind them, because … Sigue leyendo Item Response Theory Models in R and JAGS: simulation and bayesian estimation of 1PL models
Reporting survey estimates: coefficient of variation and lower confidence interval bound
I had already posted something on this sort before (click here) and I want to discuss on something else. In Colombia, for example, some official statistics institutions claim that any survey estimate with an estimated coefficient of variation (CV) greater than 15% is not reliable and, although it is published, the very figure is marked … Sigue leyendo Reporting survey estimates: coefficient of variation and lower confidence interval bound
For MAC users: weird messages when starting session in R
If you live in a Latin American country, and you have installed R in your MAC, maybe you have noticed that, after opening R, the following messages appear:During startup - Warning messages:1: Setting LC_CTYPE failed, using "C" 2: Setting LC_COLLATE failed, using "C" 3: Setting LC_TIME failed, using "C" 4: Setting LC_MESSAGES failed, using "C" … Sigue leyendo For MAC users: weird messages when starting session in R
Power of a Test and Sample Size in Complex Surveys
There are many approaches to computing sample size. In public policy evaluation, for example, one is usually tented to check if there is statistical evidence on the impact of a intervention over a population of interest. This vignette is devoted to explain the issues that you commonly find when computing sample sizes.You may have been … Sigue leyendo Power of a Test and Sample Size in Complex Surveys
Double alignment in LaTeX
Last day I was writing a proof of a theorem in $\LaTeX$, when I realized that I needed to use a symbol meaning implications for efficiency purposes. It is usual in mathematics that one thing leads to another, and it is also usual that we use $\Rightarrow$ as implication symbol. This way, I looked for … Sigue leyendo Double alignment in LaTeX
4IWAS – Who are those guys?
The 4th IWAS is coming this week. Check out this short document (in spanish) to see who are those guys that will give you personal training on statistics and public policy evaluation.
Of rankings and other demons
It has been caused a lot of noise the Synthetic Index for the Quality of Education, that has been developed jointly by ICFEs and MEN. That index is an effort to explain the reality of Colombia in terms of schools and their environment. The index has into account different components that affect the performance of schools. However, … Sigue leyendo Of rankings and other demons
Making maps in R with ggplot
This post is devoted with the quick (and free) solution of a problem that maybe some statisticians face in their jobs. Maps are becoming a valuable tool of information and you will find that R could be a comprehensive solution for this type of task.You will need to distinguish two types of data: the cartography … Sigue leyendo Making maps in R with ggplot
Writing Books with R and knitr
I am writing this post on behalf people who, like me, do not find any valuable stuff in the web, when trying to compile big documents in R with the knitr library. knitr is a basic tool for the statistician. It combines LaTeX and R in an single environment. It is useful to create elegant reports, … Sigue leyendo Writing Books with R and knitr
4th International Workshop on Applied Statistics (call for talks)
The Faculty of Statistics of Saint Thomas University in Colombia is pleased to invite you to the 4th International Workshop on Applied Statistics. The central theme of the event will be applied statistics in public policy evaluation. We will have the presence of four renamed authorities in these methodologies. They will be guiding the following … Sigue leyendo 4th International Workshop on Applied Statistics (call for talks)
Muestreo, encuestas y estadísticas oficiales 