Liberty Mutual Property Inspection, Winners Interview: 1st place, Qingchen Wang

The hugely well-liked Liberty Mutual Group: House Inspection Prediction competitors wrapped up on August 28, 2015 with Qingchen Wang at the top of a crowdedleaderboard. A total of two,362 players on two,236 teams competed to predict how many hazards a property inspector would count during a homeinspection.This blog - - outlines Qingchen's approach, and how a relative newbie to Kaggle competitions learnedfrom the community and in the end tookfirst location.The BasicsWhat was your background prior to getting into this challenge?I did my bachelors in computer science. Just after working for a couple of months at EA Sports as a computer software engineer I felt the sturdy have to have to discover statistics and machine learning as the troubles that interested me the most have been about predicting issues algorithmically. Due to the fact then Ive earned masters degrees in machine understanding and organization and Ive just began a PhD in advertising and marketing analytics.How did you get began competing on Kaggle?I had an applied machine understanding course through my masters at UCL and the course project was to compete on the Heritage Wellness Prize. Even though at the time I didnt definitely know what I was undertaking it was nonetheless a really enjoyable experience. Ive competed briefly in other competitions due to the fact, but this was the initially time Ive been capable to take component in a competition from start off to finish - - and it turned out to have been really a rewarding knowledge.What made you determine to enter this competitors?I was in a period of unemployment so I decided to function on data science competitions full-time until I identified a thing else to do. I essentially wanted to do the Caterpillar competition at 1st but decided to give this a single a speedy go because the data didnt need any preprocessing to start off. My early submissions had been not extremely good so I became determined to strengthen and ended up spending the entire time carrying out this. - retail property inspection software - What created this competition so rewarding was how much I discovered. As additional or much less a Kaggle newbie, I spent the entire two months attempting and mastering new issues. I hadnt recognized about techniques like gradient boosting trees or tricks like stacking/ blending and the assortment of approaches to handle categorical variables. At the exact same time, it was possibly the intuition that I developed through previous education that set my model apart from some of the other competitors so I was able to validate my existing information as effectively.Do you have any prior practical experience or domain know-how that helped you succeed in this competitors?Which tools did you use?I only utilized XGBoost. Its really been a understanding knowledge for me as I entered this competition possessing no thought what gradient boosted trees was. After throwing random forests at the issue and obtaining nowhere close to the best of the leaderboard, I installed XGBoost and worked truly hard on tuning its parameters.XGBoost fans or these new to boosting, verify out this great weblog by Jeremy Kun on the math behind boosting and why it does not overfitHow did you invest your time on this competition?Because the variables had been anonymous there wasnt much feature engineering to be accomplished. Instead I treated function engineering as just yet another parameter to tune and spent all of my time tuning parameters. My final answer was an ensemble of unique specifications so there have been a lot of parameters to tune.What was the run time for both training and prediction of your winning remedy?The mixture of instruction and prediction of my winning solution requires about two hours on my individual laptop (two.2ghz Intel i7 processor).Words of WisdomWhat have you taken away from this competition?A single point that I learned which Ive usually overlooked just before is that parameter tuning seriously goes a extended way in performance improvements. Whilst in absolute terms it might not be considerably, in terms of leaderboard improvement it can be of excellent value. Of course, with out the neighborhood and the public scripts I wouldnt have won and may perhaps nevertheless not know about gradient boosted trees, so a significant thanks to all of the men and women who shared their tips and code. I learned so a great deal from each sources so its been a worthwhile knowledge.Click by means of to an animated view of the community's leaderboard progression over time, and the influence of benchmark code sharing. Script by competition participant,inversionDo you have any suggestions for those just having began in data science?For these who dont currently have an established field, I strongly endorse education. All of my data science encounter and knowledge came from courses taken throughout my bachelors and masters degrees. I believe that without currently obtaining been so nicely educated in machine mastering I wouldnt have been able to adapt so quickly to the new procedures made use of in practice and the tricks that people today have talked about.There are now a number of really good education programs in data science which I recommend that absolutely everyone who wants to start in data science to appear into. For those who already have their own established fields and are carrying out data science on the side, I feel their personal approaches could be very valuable when combined with the regular machine learning techniques. Its usually critical to think outside the box and its all the far more rewarding when you bring in your personal ideas and get them to perform.Finally, dont be afraid to hit walls and grind by means of lengthy periods of attempting out concepts that dont function. A failed concept gets you 1 closer to a profitable notion, and getting a lot of failed ideas usually can result in a string of suggestions that operate down the road. Throughout this competition I attempted each and every thought I believed of and only a handful of worked. It was a combination of patience, curiosity, and optimism that got me through these two months. The same applies to finding out the technical elements of machine studying and data science. I still try to remember the discomfort that my classmates and I endured in the machine finding out courses.Just for FunIf you could run a Kaggle competitors, what issue would you want to pose to other Kagglers?Im a sports junkie so Id love to see some competitions on sports analytics. Its a shame that I missed the 1 on March Madness predictions earlier this year. Possibly one particular day Ill genuinely run a competition on this stuff.Editor's note: March Machine Learning Mania is an annual competition so you can catch it once more in 2016!What is your dream job?My dream job is to lead a data science group, preferably in an market thats complete of new and fascinating prediction problems. Id be just as pleased as a data scientist even though, but its often nice to have higher responsibilities.BioQingchen Wang is a PhD student in marketing analytics at the Amsterdam Company School, VU Amsterdam, and ORTEC. His interests are in applications of machine studying strategies to complicated genuine world complications in all domains. He has a bachelors degree in laptop science and biology from the University of British Columbia, a masters degree in machine studying from University College London, and a masters degree in company administration from INSEAD. In his free of charge time Qingchen competes in data science competitions and reads about sports.