After reading Dutch football data (Eeredivisie 2011-2012) and making a predictions display it is time to look at a few simple models to predict goals. To reiterate the data setup, each game played consists of two rows in the data frame. ...
193 search results for "anova"
N-Way ANOVA
N-Way ANOVA example Two-way analysis of variance is where the rubber hits the road, so to speak. This extends the concepts of ANOVA with only one factor to two factors. When there are two factors this means that there can be an interaction between the two factors that should be tested. As one might expect
One-Way ANOVA
One-Way ANOVA Analysis of variance is a tool used for a variety of purposes. Applications range from a common one-way ANOVA, to experimental blocking, to more complex nested designs. This first ANOVA example provides the necessary tools to analyze data using this technique. This example will show a basic one-way ANOVA. I will save the
Item Response Theory: Developing Your Intuition
Suppose that you accepted my argument from the last two posts on halo effects and bifactor models. As you might recall, I argued that when respondents complete rating scales, they predominating rely on their generalized impression with a more minor role played by the specific features that the ratings were written to measure. Consequently, we...
Book Review: R Cookbook
The R Cookbook is written by Paul Teetor, a developer with degrees in statistics and computer science, specializing in finance. The programming language R is a specialized language designed for deep statistical research, although it has some support for other mathematical fields, such as matrix algebra and signal processing. True to the O’Reilly cookbook format,
Data analysis using R – course in Essex
This course is running 1-5 October at the University of Essex. There doesn’t seem to be a website but you register by writing to maths@essex.ac.uk. Here’s what they say in their e-mail: Lecturers: Dr Werner Adler (University of Erlangen-Nuremberg; Co-author … Continue reading →
INLA: Bayes goes to Norway
INLA is not the Norwegian answer to ABBA; that would probably be a-ha. INLA is the answer to ‘Why do I have enough time to cook a three-course meal while running MCMC analyses?”. Integrated Nested Laplace Approximations (INLA) is based … Continue reading →
The Relative Importance of Predictors – Let the Games Begin!
What's the one thing we need to do?
Marketing researchers are asked this question frequently whenever they analyze customer satisfaction data. A company wishing to increase sales or limit churn wants to focus only on the most important determinants of those outcomes. Given the limitations imposed by the available customer survey data, this strategic question is transformed quickly into a methodological one concerning how...
Adventures at My First JSM (Joint Statistical Meetings) #JSM2012
During the past few decades that I have been in graduate school (no, not literally) I have boycotted JSM on the notion that “I am not a statistician.” Ok, I am a renegade statistician, a statistician by training. JSM 2012 was held in San Diego, CA, one of the best places to spend a week during the summer. This...
Example 9.36: Levene’s test for equal variances
The assumption of equal variances among the groups in analysis of variance is an expression of the assumption of homoscedasticity for linear models more generally. For ANOVA, this assumption can be tested via Levene's test. The test is a function of the residuals and means within each group, though various modifications are used, including the Brown-Forsythe...
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
