Briefly - Hopper is something new in the travel / local space. In their own words: What if you could plan an amazing trip based on a vague idea — like “spring surfing in California” or “Mediterranean cruise”? What if...

Some facts and some speculation. Definition Volatility is the annualized standard deviation of returns — it is often expressed in percent. A volatility of 20 means that there is about a one-third probability that an asset’s price a year from now will have fallen or risen by more than 20% from its present value. In … Continue reading →

Steve Peterson writes: I recently submitted a proposal on applying a Bayesian analysis to gender comparisons on motivational constructs. I had an idea on how to improve the model I used and was hoping you could give me some feedback. The data come from a survey based on 5-point Likert scales. Different constructs are measured […]The post Transformations for non-normal data appeared first on Statistical Modeling, Causal Inference, and Social…

A colleague asked if I had any material for a course in sample surveys. And indeed I do. See here. It’s all the slides for a 14-week course, also the syllabus (“surveyscourse.pdf”), the final exam (“final2012.pdf”) and various misc files. Also more discussion of final exam questions here (keep scrolling thru the “previous entries” until […]The post A course in sample surveys for political science appeared first on Statistical Modeling,…

UPDATE: THE BLOG/SITE HAS MOVED TO GITHUB. THE NEW LINK FOR THE BLOG/SITE IS patilv.github.io and THE LINK TO THIS POST IS: http://bit.ly/1jccIBN. PLEASE UPDATE ANY BOOKMARKS YOU MAY HAVE.This post uses animated choropleths to visualize violent crime r...

Consider a standard linear regression setting with \(K\) regressors and sample size \(N\). We will say that an estimator \(\hat{\beta}\) is consistent for a treatment effect (``T-consistent") if \(plim \hat{\beta}_k = {\partial E(y|x) }/{\partial x_k}\...

There’s a paradigm in applied statistics that goes something like this: 1. There is a scientific or policy question of some theoretical or practical importance. 2. Researchers gather data on relevant outcomes and perform a statistical analysis, ideally leading to a clear conclusion (p less than 0.05, or a strong posterior distribution, or good predictive […]The post How to think about the statistical evidence when the statistical evidence can’t be…

The simplest experimental design is the completely randomized design with 1 factor. In this design, each experimental unit is randomly assigned to each factor level. This design is most useful for a homogeneous population (one that does not have major differences between any sub-populations). It is appealing because of its simplicity and flexibility – it can […]

Andrew Gelman says that as a philosopher, I should appreciate his blog today in which he records his frustration: “Against aggressive definitions: No, I don’t think it helps to describe Bayes as ‘the analysis of subjective beliefs’…” Gelman writes: I get frustrated with what might be called “aggressive definitions,” where people use a restrictive definition of something […]

I don't think I've ever been forwarded one link on the web more than I have been forwarded the edge.org post on "What scientific idea is ready for retirement?". Here are a few of the comments with my responses. I'm … Continue reading →

I get frustrated when people use aggressive overly restrictive definitions of something they don’t like. [I originally used the term "aggressive definitions" but I think the whole "aggressive" thing was misleading as it implies aggressive intent, which I did not mean to imply. So I changed to "overly restrictive definition."] Here’s an example of an […]The post Against overly restrictive definitions: No, I don’t think it helps to describe Bayes…

I have been busy working on syllabuses for my Spring 2014 courses at NYU, and that's why posting has been more haphazard than usual. I don't think I have said much about my teaching here on the blog, so let me take this opportunity to introduce the classes that I teach. Statistics For Management I (link) This is an introductory statistics course with a business/management emphasis. Many students take this…