Math problems in Industry Dr. Jonathan D Adler

Questions about math jobs What kind of jobs are actually out there for math students? Anything besides teaching or accounting? What jobs are actually enjoyable? What is the work like in these jobs? What kind of skills do I need to get one of these jobs? Who should I be asking these questions to? 2

Allow me to answer your questions 3 By telling you my life story

College: Worcester Polytechnic Institute 4

About me I became a math major because I liked taking math classes When I was an undergraduate in math I had no idea what kinds of jobs I could get. I figured the breakdown was: 1.High school math teacher 2.College math professor 3.Industry??? Naturally, as someone who liked taking math classes, (2) seemed like the natural choice for me. Decided to get a BS/MS so that I could then get a PhD Maybe more useful for industry I guess? Did my master’s thesis on graph theory and monadic second order logic 5

Maybe being a professor wasn’t right for me Had summer research and internships, and didn’t like doing research If being a math professor means doing a lot of trying to find exact solutions and coming up fruitless, maybe it wasn’t right for me. My internship was fun! I solved problems, and wrote code people could use! Maybe industry would be right for me. I had a few more internships: Did a project with the BOSE Corporation numerically modeling screw insertion into plastic Worked at Boeing making mathematical forecasts of how aircraft demand would change in the near future It felt like math 6

Finished school, time to find a job When searching for my first job, there were zero non- teaching jobs labelled “mathematician” Lots of jobs would take math majors “If they’re hiring math majors, that must mean I’ll be doing math! Let’s see how it goes!” Ended up getting a job at a company called Vistaprint 7

First real job: Vistaprint 8

Vistaprint Vistaprint sells custom printed business cards online Referred by a friend (hiring math majors!) Job description: maintain the statistical models used to forecast the business 9

Vistaprint problem 1: customer segmentation Vistaprint had millions of customers Some customers spent a little money holiday greeting cards Some customers spent hundreds of dollars on materials to promote their small business Some customers paid Vistaprint to host their small business website Every day, Vistaprint sends an with a coupon What message should you put in the How much should the coupon save? Proper answer can dramatically increase the revenue to Vistaprint 10

Vistaprint problem 1: customer segmentation Idea, use statistics to split customers by their attributes Analyze the customers in each group to see what type of customers they are Send an different to each cluster 11 Run an A/B test to see what the right coupon value is Try sending two coupons, one for $5 off and one for $10 off, and see which does better If the $10 does well enough to offset the increased cost, use it again in the future

Vistaprint problem 2: the general analytics problem The vast majority of my work was answering questions like this: “Do customers who buy business cards tend to buy holiday cards as well?” Seems like an obvious question, but how do you turn it into something you can answer with numbers? What does “buying business cards” mean? Look at the past year’s data and see if they have made any purchases that included business cards What does “tend to buy” mean? See if they put a holiday card in the order with business cards, or maybe ordered within the next month What should we compare this to? Customers who hadn’t ordered any business cards maybe? We had data on every customer, order and product we sold Look in the data for every order over the past 12 months, and count the times they included business cards and holiday cards, compare the percent of orders with biz and hol cards to the total with biz cards Really want to answer the question they didn’t ask: Can we get more orders for holiday cards by marketing to the people who bought business cards? 12

Difference between “Math” and “mathy” 13 “mathy” work “Math” work Office work Proving theorems Developing new methods Finding new applications for existing methods Using existing methods in conventional ways Manipulating data in interesting ways Manipulating data in Excel Manipulating charts in PowerPoint Pressing the button that needs to be pressed Going to meetings Every math undergrad thinks they will end up here Interesting jobs for math undergrads fall here most jobs for math undergrads fall here Interesting jobs for math grad students fall here Vistaprint job (as hired)

Difference between “Math” and “mathy” 14 “mathy” work “Math” work Office work Proving theorems Developing new methods Finding new applications for existing methods Using existing methods in conventional ways Manipulating data in interesting ways Manipulating data in Excel Manipulating charts in PowerPoint Pressing the button that needs to be pressed Going to meetings Job titles Researcher Scientist Business analyst Analyst Analytics / Data Science Machine learning expert/ Senior data scientist/ Statistician/ Operations researcher/ Advanced analytics expert

Difference between “Math” and “mathy” Nothing “wrong” with being lower on the ladder Just because it isn’t “Math” doesn’t mean it isn’t interesting and a good brain workout Way more jobs lower on the ladder Too high up and your stuff doesn’t get used Thinking all the time is exhausting You can move up the ladder Find a new area to do something mathematical Improve a current process with clever tricks Automate a process that is boring 15

Vistaprint problem 3: forecasting and quality control Problem: Vistaprint had data on revenue for every order for the past few years On a recent Tuesday had a bug which went undetected and lowered sales dramatically A director ed my department and asked for history of sales over all Tuesdays, was going to take the average of that and if you’re below it you can tell there is a bug Options: a)Run a query on the database to get the data and it to him b)Point out it’s a much more complicated and interesting problem Sales are increasing over time Only interested in sudden drops How do you correctly determine how low is “too low?” What if you want to detect it more quickly than that? 16

Vistaprint problem 3: forecasting and quality control I was loud and complained we were doing things the wrong way, and ultimately was put in charge of a team to create a system of statistical quality control tools to detect anomalies Normalize the data: By day of week By time of year By if it is a holiday Compare to recent few hours for sudden drops, previous week for more long term decay. Use mean and standard deviation to detect when an drop is sufficiently large 17

Skills you should get before leaving school To be decent in industry you need to know Basic databases (intro database course) Everyone stores their data in SQL (or equivalent) Since industry mathematics is all based on data, you need to be able to manipulate it Basic programming (intro programming course) Don’t have to be a CS wizard, but do need to be able to understand loops, functions, and the simple stuff Language isn’t a big deal (R, Python, and MATLAB all okay), but need to be able to do more than just run built in functions Basic statistics (intro statistics course) Everything has uncertainty Need to be able to understand how the uncertainty of the data will affect your results Unfortunately assumptions from class never hold, so get ready to roll with it 18

Skills you should get before leaving school To be excellent in industry you need Everything from the previous list The ability to learn more things Projects and internships are potentially great ways to learn how to learn 19

Vistaprint (continued) By the time I left Vistaprint I was: Building new models for forecasting sales volumes using much more advanced methodologies If you have the previous three years of sales volumes, how can you predict what next year’s will be? By day? Leading a team to build a statistical quality control tool for sales metrics Dabbling in recommendation engine to decide what products to show to users of the site Given that you know a lot about the person visiting the site, how can you decide what products to recommend to them? 20

Next real job: Boeing 21

Boeing Boeing sells airplanes Worked in the market forecasting group: helped predict number of airplanes the world would need in 20 years Example problem: suppose you have historic data on when aircraft were built and when they were scrapped; how can you predict when airplanes that are currently flying will be scrapped? Answer is affected by things like economic downturns This is a statistical analysis, given you have an airplane and you know it’s model and age, what is the probability it will be scrapped in a particular year? Model and age are independent variables, predicting scrapped probability We used a logistic regression ultimately 22

Boeing problem 1: airplane analysis 23 This is a statistical analysis, given you have an airplane and you know it’s model and age, what is the probability it will be scrapped in a particular year? Model and age are independent variables, predicting scrapped probability We used a logistic regression ultimately ModelTail NumberAgeUsageYearStatus 727N Freight2015Flying 727N Freight2015Parked 737N Freight2015Scrapped 737N Passenger2015Flying 737N Passenger2015Flying

Boeing problem 2: passengers per seat 24 To know how many airplanes will be in the world in 20 years, it helps to know how many people will be riding in each plane Load factor is the passengers per seat (ex: 60 passengers and 100 seats = 60%) How to predict future load factors from historic data

Boeing While job had some math, ultimately I fell lower on the ladder “I know what will help get me higher up that ladder! More school!” Maybe I’ll realize I wanted to be a professor after all 25

Grad school 2: Arizona State University 26

Arizona State University Went to get a PhD in Industrial Engineering Liked the operations research part of math, but that wasn’t in the math department of ASU Conveniently also taught me statistics and data mining Researched routing policies for electric vehicles (graph theory meets optimization meets transportation) Being an academic is: An extremely difficult job to get in the first place Wasn’t ultimately rewarding to me Academia: publish papers that move the field forward slightly Industry: make models and tools that can help your one particular company a lot 27

Sample problem: Brownie text analytics A local brownie company had a website where people could order brownies online Some people sent them to friends and family Businesses sent them to clients and customers Brownie company wanted to know how to split business orders and consumer orders Different customers would get different catalogs Gift messages on the brownie boxes held the key –use text analytics to decide the purpose of the order Fancy way of just counting the business words and the consumer words 28 THANK YOU ALL FOR YOUR AND HARD WORK, IT IS TRULY APPRECIATED BY THE MANAGEMENT TEAM CONGRATULATIONS AND BEST OF LUCK ON YOUR NEW JOB! WE ARE VERY PROUD OF YOU! LOVE MOM

Next job: Promontory Growth and Innovation 29

Promontory Growth and Innovation PGI was a “management consulting” company, in that we helped companies increase profitability I was a lead on the team that took client data and tried to figure out what’s going on End up using a grab bag of mathematical techniques Data mining Bayesian statistics Linear programming Graph theory Pretty high up the “mathy” ladder yet still got to deliver real value During the job I accidentally became a Software developer Project manager 30

Promontory Growth and Innovation problem: staffing A hospital has hourly staff, which work in different departments and jobs (sometimes multiple) The staff is taking a lot of overtime hours How much of that overtime is necessary? A matching problem: The departments and jobs have a demand that needs to be filled The staff has a supply There is a bipartite graph between those two sets, and the edges are if an employee can do that job A linear program can be solved to figure out how much of the demand can be served before needing overtime 31

32 Promontory Growth and Innovation problem: staffing Joseph Susan Mary ER OR Pharmacy Recovery

Grad school only sort of helps Graduate school can teach you how to learn on your own Essential for jobs higher up the mathy ladder Grad school may teach you some of the three key skills (statistics, databases, programming) An MS or PhD may open doors for some jobs higher up on the mathy ladder A doctorate without experience is an even harder hire Has a huge opportunity cost if you’re not careful 33

Today: Microsoft Studios 34

Microsoft Studios Microsoft makes lots of first party games: Halo, Minecraft, Gears of War, etc. Each game creates data (player kills and deaths, times logged in, in game purchases) That data can be used to: Prevent cheating Forecast sales of future games Improve the game itself Data from one game can be shared with others for a better overall picture I am a member of the (just starting) shared analytics across all titles 35

Microsoft Studios problem: cheat detection Sometimes when people play games they cheat, how do you detect these? Look for anomalies in the data: People who have lap times in a racing game that are faster than physically possible People who have scores 3 standard deviations above the mean People who submit multiple scores at once 36

Questions (revisited) What kind of jobs are actually out there for math students? Teaching jobs – high school and small liberal arts professors Industry jobs – helping companies by using math on their data Research jobs – doing academic research to move the field forward What is the work like in these jobs? Lots of crunching numbers and using math to answer questions What kind of skills do I need to get one of these jobs? Stats, programming, databases, and some focused math classes Who should I be asking these questions to? People who have been down this road before. Reach out to people like me either directly or through your local university 37

Questions? (For a copy of this presentation go to: 38