## Estimating Population Size: Animals and Web Pages

Thinking about all of the things in the statistical world that we can estimate, the one that has always perplexed me is estimating the size of an unknown population $$N$$. Usually when we compute estimates based on samples, we involve the size of the sample $$n$$ somewhere, thus we take “size” for granted — the size of a sample is known. We also make inferences based on sample statistics using theory such as the Central Limit Theorem, but seem to never care about the population size $$N$$, we either know it, or assume it is infinite. But, in fields like ecology and environmental studies, this attitude of gluttony is dangerous!

In the summers I spend a lot of time in the Eastern Sierra where there are deer and bears. These animals are so large that we cannot consider their population in the area to be infinite (like we may with ants or bacteria). A matter of fact, one of our local animal behavior specialists knows the exact number of bears that live in my mountain community. I always had just assumed he spent all day tracking down the local bears and marking them with radio collars. There must be some […]

## Summary of My First Trip to Strata #strataconf

In this post I am goIing to summarize some of the things that I learned at Strata Santa Clara 2013. For now, I will only discuss the conference sessions as I have a much longer post about the tutorial sessions that I am still working on and will post at a later date. I will add to this post as the conference winds down.

The slides for most talks will be available here but not all speakers will share their slides.

This is/was my first trip to Strata so I was eagerly awaiting participating as an attendant. In the past, I had been put off by the cost and was also concerned that the conference would be an endless advertisement for the conference sponsors and Big Data platforms. I am happy to say that for the most part I was proven wrong. For easier reading, I am summarizing talks by topic rather than giving a laundry list schedule for a long day and also skip sessions that I did not find all that illuminating. I also do not claim 100% accuracy of this text as the days are very long and my ears and mind can only process so much data when […]

## A New Data Toy — Unboxing the Raspberry Pi

Last week I received two Raspberry Pis in the mail from AdaFruit and just now have some time to play with them. The Raspberry Pi is a minimal computer system that is about the size of a credit card. In the embedded systems community, the excitement is for obvious reasons, but I strongly believe that such a device can help collect and use data to help us make better decisions because not only is it a computer, but it is small and portable.

For development, Raspberry Pi can connect to a television (or other display) via HDMI or composite video (the “yellow” plug for those still stuck in the 1900s haha). A keyboard, mouse and other devices can be connected via two USB ports. A powered hub can provide support for even more devices. There are also various pins for connecting to a breadboard for analyzing analog signals, for a camera or for an external (or touchscreen) display. An SD Card essentially serves as the hard disk and probably a portion of the RAM. The more recent Model B ships with 256MB RAM. Raspberry Pi began shipping in February 2012 and these little guys have been very difficult to get […]

## 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 time, I had no excuse not to go, and I figured that in order to get my Ph.D. in Statistics, I have to have been to at least one JSM. […]

## “Hold Only That Pair of 2s?” Studying a Video Poker Hand with R

Whenever I tell people in my family that I study Statistics, one of the first questions I get from laypeople is “do you count cards?” A blank look comes over their face when I say “no.”

Look, if I am at a casino, I am well aware that the odds are against me, so why even try to think that I can use statistics to make money in this way? Although I love numbers and math, the stuff flows through my brain all day long (and night long), every day. If the goal is to enjoy and have fun, I do not want to sit there crunching probability formulas in my head (yes that’s fun, but it is also work). So that leaves me at the video Poker machines enjoying the free drinks. Another positive about video Poker is that \$20 can sometimes last a few hours. So it should be no surprise that I do not agree with using Poker to teach probability.  Poker is an extremely superficial way to introduce such a powerful tool and gives the impression that probability is a way to make a quick buck, rather than as an important tool in science and society. The […]

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## SIGKDD 2011 Conference — Days 2/3/4 Summary

<< My review of Day 1.

I am summarizing all of the days together since each talk was short, and I was too exhausted to write a post after each day. Due to the broken-up schedule of the KDD sessions, I group everything together instead of switching back and forth among a dozen different topics. By far the most enjoyable and interesting aspects of the conference were the breakout sessions.

Keynotes

KDD 2011 featured several keynote speeches that were spread out among three days and throughout the day. This year’s conference had a few big names.

Steven Boyd, Convex Optimization: From Embedded Real-Time to Large-Scale Distributed. The first keynote, by Steven Boyd, discussed convex optimization. The goal of convex optimization is to minimize some objective function given linear constraints. The caveat is that the objective function and all of the constraints must be convex (“non-negative curvature” as Boyd said). The goal of convex optimization is to turn the problem into a linear programming problem. We should care about convex optimization because it comes from some beautiful and complete theory like duality and optimality conditions. I must say, that whenever I am chastising statisticians, I often say that all they […]

## SIGKDD 2011 Conference — Day 1 (Graph Mining and David Blei/Topic Models)

I have been waiting for the KDD conference to come to California, and I was ecstatic to see it held in San Diego this year. AdMeld did an awesome job displaying KDD ads on the sites that I visit, sometimes multiple times per page. That’s good targeting!

Mining and Learning on Graphs Workshop 2011

I had originally planned to attend the 2-day workshop Mining and Learning with Graphs (MLG2011) but I forgot that it started on Saturday and I arrived on Sunday. I attended part of MLG2011 but it was difficult to pay attention considering it was my first time waking up at 7am in a long time. The first talk I arrived for was Networks Spill the Beans by Lada Adamic from the University of Michigan. Adamic’s presented work involved inferring properties of content (the “what”) using network structure alone (using only the “who”: who shares with whom). One example she presented involved questions and answers on a Java programming language forum. The research problem was to determine things such as who is most likely to answer a Java beginner’s question: a guru, or a slightly more experienced user? Another research question asked what dynamic interactions tell us […]

## Want to Build a Research Server?

I am usually pretty reserved with cash, but after working full-time for six months, I finally decided to spend some of my money on building a new research development server. This process was long overdue and the reason it took me so long to commit to this project was all of the new technology developed since building my last server. This “new technology” can be pretty confusing unless one specializes in computer architecture. I want to share what I have learned throughout this process, while giving some background. These are only my opinions, and I may be wrong on some things as I am not a hardware expert. I encourage you to read and learn more on your own.

The CPU/Processor

If you are reading this article, I probably do not need to explain what the CPU/processor does. For high performance computing, you will want to get a CPU that is very “fast” and also has multiple cores. The definition of the word “fast” is in the eyes of the beholder and typically refers to more than just clock speed (GHz). In the constant war between AMD and Intel, I stick with Intel. AMD processors are powerful, but they seem […]

## Review of 2011 Data Scientist Summit

Some time over the past 6 weeks I randomly saw a tweet announcing the “Data Scientist Summit” and shortly below it I saw that it would be held in Las Vegas at the Venetian. Being a Data Scientist myself is reason enough to not pass up this opportunity, but Vegas definitely sweetens the deal! On Wednesday I woke up at 6am to partake on the 5.5 hour voyage to Las Vegas.

The Pre-Party

The Venetian and all close hotels were booked, so I ended up at the Aria; a new experience. The hotel is beautiful and very ritzy. I had heard that the rooms were very technologically advanced but I wasn’t prepared for the recorded welcome message, music and automatic shades opening upon entry to the room. The Aria is a geek’s paradise. Everything is computerized. Key cards are “waved” rather than swiped, lights are turned on/off and dimmed by use case (“sleep”, “read” etc.), rather than manually. There are no paper “Do Not Disturb” signs; rather, a switch on the wall (or via TV) toggles an indicator light outside the door. And the best part… Internet is FREE!

The rhododendrons hydrangeas are real! Work desk panel contains Ethernet, […]