Category Archives: Books

The First Sentence of the Great Analytics Novel

Thedarktower7 I’ve written many times before about the importance of promoting O.R. to the general public. One of the ideas that’s been suggested by several people is the possibility of writing a work of fiction whose main character (our hero) is an O.R./Analytics person. I still believe this is a great idea, if executed properly.

Today, my wife brought to my attention The Bulwer-Lytton Fiction Contest, which, according to their web page, consists of the following:

Since 1982 the English Department at San Jose State University has sponsored the Bulwer-Lytton Fiction Contest, a whimsical literary competition that challenges entrants to compose the opening sentence to the worst of all possible novels. The contest (hereafter referred to as the BLFC) was the brainchild (or Rosemary’s baby) of Professor Scott Rice, whose graduate school excavations unearthed the source of the line “It was a dark and stormy night.” Sentenced to write a seminar paper on a minor Victorian novelist, he chose the man with the funny hyphenated name, Edward George Bulwer-Lytton, who was best known for perpetrating The Last Days of PompeiiEugene AramRienziThe CaxtonsThe Coming Race, and – not least – Paul Clifford, whose famous opener has been plagiarized repeatedly by the cartoon beagle Snoopy. No less impressively, Lytton coined phrases that have become common parlance in our language: “the pen is mightier than the sword,” “the great unwashed,” and “the almighty dollar” (the latter from The Coming Race, now available from Broadview Press).

Just like an awful first sentence can be a good indicator of a terrible book, the converse can also be true. Take, for example, the first sentence of Stephen King’s The Dark Tower series, which I happen to be reading (and loving) as we speak:

The man in black fled across the desert, and the gunslinger followed.

It’s such a strong, mysterious, and captivating sentence…

…which brings me to the point of this post. If it’s going to be difficult to write The Great Analytics Novel, what if we start by thinking about what would be the perfect, most compelling sentence to start such a novel? Yes, I propose a contest. Let’s use our artistic abilities and suggest starting sentences. Feel free to add them as comments to this post. Who knows? Maybe someone will get inspired and start writing the novel.

Here’s mine:

Upon using the word “mathematical” he knew he had lost the battle for, despite the dramatic cost savings, their logical reasoning was instantly halted, like a snowshoe hare frozen in fear of its chief predator: the Canada lynx.

I can’t wait to read your submissions!

4 Comments

Filed under Analytics, Books, Challenge, INFORMS Public Information Committee, Motivation, Promoting OR

Improving a Homework Problem from Ragsdale’s Textbook

UPDATE (1/15/2013): Cliff Ragsdale was kind enough to include the modification I describe below in the 7th edition of his book (it’s now problem 32 in Chapter 6). He even named a character after me! Thanks, Cliff!

When I teach the OR class to MBA students, I adopt Cliff Ragsdale’s textbook entitled “Spreadsheet Modeling and Decision Analysis“, which is now in its sixth edition. I like this book and I’m used to teaching with it. In addition, it has a large and diverse collection of interesting exercises/problems that I use both as homework problems and as inspiration for exam questions.

One of my favorite problems to assign as homework is problem number 30 in the Integer Linear Programming chapter (Chapter 6). (This number refers to the 6th edition of the book; in the 5th edition it’s problem number 29, and in the 4th edition it’s problem number 26.) Here’s the statement:

The emergency services coordinator of Clarke County is interested in locating the county’s two ambulances to maximize the number of residents that can be reached within four minutes in emergency situations. The county is divided into five regions, and the average times required to travel from one region to the next are summarized in the following table:

The population in regions 1, 2, 3, 4, and 5 are estimated as 45,000,  65,000,  28,000,  52,000, and 43,000, respectively. In which two regions should the ambulances be placed?

I love this problem. It exercises important concepts and unearths many misconceptions. It’s challenging, but not impossible, and it forces students to think about connecting distinct—albeit related—sets of variables; a common omission in models created by novice modelers. BUT, in its present form, in my humble opinion, it falls short of the masterpiece it can be. There are two main issues with the current version of this problem (think about it for a while and you’ll see what I mean):

  1. It’s easy for students to eyeball an optimal solution. So they come back to my office and say: “I don’t know what the point of this problem is; the answer is obviously equal to …” Many of them don’t even try to create a math model.
  2. Even if you model it incorrectly, that is, by choosing the wrong variables which will end up double-counting the number of people covered by the ambulances, the solution that you get is still equal to the correct solution. So when I take points off for the incorrect model, the students come back and say “But I got the right answer!”

After a few years of facing these issues, I decided I had had enough. So I changed the problem data to achieve the following (“evil”) goals:

  1. It’s not as easy to eyeball an optimal solution as it was before.
  2. If you write a model assuming every region has to be covered (which is not a requirement to begin with), you’ll get an infeasible model. In the original case, this doesn’t happen. I didn’t like that because this isn’t an explicit assumption and many students would add it in.
  3. If you pick the wrong set of variables and double-count the number of people covered, you’ll end up with an incorrect (sub-optimal) solution.

These improvements are obtained by adding a sixth region, changing the table of distances, and changing the population numbers as follows:

The new population numbers (in 1000’s) for regions 1 through 6 are, respectively, 21, 35, 15, 60, 20, and 37.

I am now much happier with this problem and my students are getting a lot more out of it (I think). At least I can tell you one thing: they’re spending a lot more time thinking about it and asking me intelligent questions. Isn’t that the whole purpose of homework? Maybe they hate me a bit more now, but I don’t mind practicing some tough love.

Feel free to use my modification if you wish. I’d love to see it included in the 7th edition of Cliff’s book.

Note to instructors: if you want to have the solution to the new version of the problem, including the Excel model, just drop me a line: tallys at miami dot edu.

Note to students: to preserve the usefulness of this problem, I cannot provide you with the solution, but if you become an MBA student at the University of Miami, I’ll give you some hints.

7 Comments

Filed under Books, Integer Programming, Modeling, Teaching

The “Real” Reason Bill Cook Created the TSP App

By now, most people are aware of the latest Internet meme Texts from Hillary which is, by the way, hilarious. You’re also probably aware that Bill Cook created an iPhone App that allows one to solve traveling salesman problems (TSP) on a mobile phone! If you like optimization, you have to give this App a try; and make sure to check out the Traveling Salesman book too!

Inspired by Texts from Hillary I finally figured out the “real” reason why Bill Cook created the App. Here it is:

1 Comment

Filed under Applications, Books, iPhone, Meme, People, Promoting OR, Traveling Salesman Problem

Best Known European Book on LP, in 1966

Today, as I entered my department’s Xerox/coffee room to make myself some tea, I noticed a big pile of old books and a note from one of my colleagues saying they were up for grabs. As I browsed through the titles, one of them caught my attention:

And here’s the text that appears on the flaps of the outer paper cover:

The publication date is 1966. And here’s an interesting quote:

“The best-known European book on linear programming. Considered one of the most complete studies of the field ever written,…”

I must confess I didn’t know about this book, but I decided to keep it for its (potential) historical value. A little Googling led me to discover that Adi Ben-Israel wrote a half-page SIAM Review about this book in 1967 (volume 9, no. 3, p. 608). Here are some highlights:

“This book is, in my opinion, among the best in the class of general reference and self-instruction L.P. texts presently available, and as such is most valuable to practitioners and students of L.P.”

Later on Adi also says that the book has “Many well-chosen, worked out examples.” That sounds pretty good! I haven’t had time to browse through it yet, but if anyone knows about this book, I’d love to hear your thoughts.

Leave a comment

Filed under Books, Linear Programming