Once again I have decided to pimp my blog. This time is a significant change: the name. This blog began a long time ago. It was 2006; I was 22-year-old, and I was enrolled in a Master of Science in Statistics. I had plenty of doubts about statistics, data science, and uncertainty (fortunately, some of … Sigue leyendo Data Literacy
Etiqueta: Stats
Multilevel Modeling of Educational Data using R (Part 1)
Linear models fail to recognize the effect of clustering due to intraclass correlation accurately. However, under some scenarios force you to take into account that units are clustered into subgroups that at the same time are nested within larger groups. The typical example is the analysis of standardized tests, where students are grouped in schools, … Sigue leyendo Multilevel Modeling of Educational Data using R (Part 1)
#PredictiveCOL – Forecasting Colombia’s peace plebiscite (final update)
For sure, this is the more exciting forecast I have ever done. On one hand, I am Colombian guy, and I really want to live in a peaceful country, and I do want a better place for raising my children. On the other hand, I am very serious when it comes to forecasting.Maybe you have … Sigue leyendo #PredictiveCOL – Forecasting Colombia’s peace plebiscite (final update)
My talk in Bogotá – Pvalues: use and abuse
Did you know that American Statistical Association (ASA) made a disclaimer about the proper use of p-values? Moreover, ASA (the oldest scientific association in the USA) claimed that: P-values can indicate how incompatible the data are with a specified statistical model. P-values do not measure the probability that the studied hypothesis is true, or the … Sigue leyendo My talk in Bogotá – Pvalues: use and abuse
Voting intention and calibration estimators – My article in CJS
During the last few years, I've been very interested in electoral studies. If you have been a reader of this blog, maybe you could remind that I predicted, some years ago, that Santos was going to win the presidential elections in Colombia. From that very election (Zuluaga won in the first round, while Santos won … Sigue leyendo Voting intention and calibration estimators – My article in CJS
Estimating the change of two measures by equating
Suppose that we have a survey (baseline + follow-up) in which we ask to some people about a variable of interest. If we follow that cohort, or even some if we ask later to some other people, we can estimate the net change of that very variable in the scale of the baseline by means … Sigue leyendo Estimating the change of two measures by equating
Simulando la paradoja de Lord en R
Es difícil no mencionar la paradoja de Lord en un curso de métodos estadísticos o de modelación estocástica. Además, si se utiliza el software estadístico más importante del mundo, R, entonces esta entrada es de su interés. La paradoja de Lord resume el análisis de dos estadísticos que analizan el peso promedio de algunos estudiantes en … Sigue leyendo Simulando la paradoja de Lord en R
La paradoja de Lord
En un artículo llamado A Paradox in the Interpretation of Group Comparisons publicado en Psychological Bulletin, Lord (1967) hizo famosa la siguiente historia controversial:Una universidad está está interesada en investigar los efectos de la dieta nutricional que sus estudiantes consumen en el restaurante del campus. Se recolectaron varios tipos de datos incluyendo el peso de cada … Sigue leyendo La paradoja de Lord
Estadística aplicada en la evaluación de la educación – Call for papers
La Revista Comunicaciones en Estadística ha alcanzado en muy poco tiempo una connotación importante en el ámbito local. Como prueba de ello, la revista fue aceptada en el Current Index to Statistics y además Colciencias decidió clasificarla en la categoría B en Publindex. Este es un gran logro para su consejo editorial, en cabeza de … Sigue leyendo Estadística aplicada en la evaluación de la educación – Call for papers
¿Datos faltantes? Utilice la imputación múltiple – Caso: regresión simple
Una característica común en cualquier análisis estadístico es la aparición de datos faltantes después de la recolección de la información. Es bien sabido que lo mejor que el investigador puede hacer para palear este inconveniente es prevenirlo desde el diseño del estudio. Sin embargo, en caso de que aparezcan, lo peor que se puede hacer … Sigue leyendo ¿Datos faltantes? Utilice la imputación múltiple – Caso: regresión simple
Parametric bootstrap
Assume we want to know the mean square error (MSE) of the sample median as a estimator of a population mean under normality. As you know, this is not a trivial problem. We may take advantage of the Bootstrap method and solve it by means of simulation. This way, for $b=1,\ldots, B$, we generate $X_{b1},\ldots, X_{bn} \sim … Sigue leyendo Parametric bootstrap
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
Muestreo, encuestas y estadísticas oficiales 