1617 search results for "regression"

Happy Birthday Florence Henderson

February 9, 2013
By
Happy Birthday Florence Henderson

As a celebration of Florence Henderson’s 79th birthday (on February 14), I have created this scatterplot to use in my regression course. The plot depicts the relationship between time spent on mathematics homework outside of school (expressed as z-scores) and … Continue reading →

Read more »

Quantifying the international search for meaning

February 9, 2013
By
Quantifying the international search for meaning

Inspired by Preis et al.’s article Quantifying the advantage of looking forward, recently published in Scientific Reports (one of Nature publishing group’s journals), I wondered if similar big-data web-based research methods might address a question even bigger than how much different countries wonder about next year. How about the meaning of life. Who is searching

Read more »

Extracting the Epidemic Model: Going Beyond Florence Nightingale Part II

February 7, 2013
By
Extracting the Epidemic Model: Going Beyond Florence Nightingale Part II

This is the second of a two part reexamination of Florence Nightingale's data visualization based on her innovative cam diagrams (my term) shown in Figure 1. Figure 1. Nightingale's original cam diagrams (click to enlarge)RecapIn Part I, I showed that FN applied sectoral areas, rather than a pie chart or...

Read more »

Modelling memory and news trajectories

February 6, 2013
By
Modelling memory and news trajectories

Modelling memory In the text below I present two models I've made to quantify and visualise the diverging trajectories of memory and news events, and conclude that linear regression may be used to test which model best describes the story. First, though, I contextualise this with an illustration from the...

Read more »

The new Stan 1.1.1, featuring Gaussian processes!

February 6, 2013
By
The new Stan 1.1.1, featuring Gaussian processes!

We just released Stan 1.1.1 and RStan 1.1.1 As usual, you can find download and install instructions at: http://mc-stan.org/ This is a patch release and is fully backward compatible with Stan and RStan 1.1.0. The main thing you should notice is that the multivariate models should be much faster and all the bugs reported for The post The...

Read more »

Collinearity and stepwise VIF selection

February 5, 2013
By
Collinearity and stepwise VIF selection

Collinearity, or excessive correlation among explanatory variables, can complicate or prevent the identification of an optimal set of explanatory variables for a statistical model. For example, forward or backward selection of variables could produce inconsistent results, variance partitioning analyses may be unable to identify unique sources of variation, or parameter estimates may include substantial amounts

Read more »

Natura non facit saltus

February 5, 2013
By
Natura non facit saltus

(see John Wilkins’ article on the – interesting – history of that phrase http://scienceblogs.com/evolvingthoughts/…). We will see, this week in class, several smoothing techniques, for insurance ratemaking. As a starting point, assume that we do not want to use segmentation techniques: everyone will pay exactly the same price. no segmentation of the premium And that price should be related to...

Read more »

Proposed techniques for communicating the amount of information contained in a statistical result

February 5, 2013
By
Proposed techniques for communicating the amount of information contained in a statistical result

A couple of weeks ago, I posted about how much we can expect to learn about the state of the world on the basis of a statistical significance test. One way of framing this question is: if we’re trying to come to scientific conclusions on the basis of statistical results, how much can we update

Read more »

Proposed techniques for communicating the amount of information contained in a statistical result

February 4, 2013
By
Proposed techniques for communicating the amount of information contained in a statistical result

A couple of weeks ago, I posted about how much we can expect to learn about the state of the world on the basis of a statistical significance test. One way of framing this question is: if we’re trying to come to scientific conclusions on the basis of statistical results, how much can we update

Read more »

"I don’t wanna grow up": Age / value relationships for football players

February 1, 2013
By
"I don’t wanna grow up": Age / value relationships for football players

Let's get back to the age-value relationship from my last post. I did some more plotting to see on which position this inversed U-shaped relationship is strongest. Please note, that I use a dataframe called eu.players throughout this post, which holds downloaded football player information from transfermarkt.de.But first, let us get back to the original graph.

Read more »