February 18th, 2014
Recently, I received a slide deck extolling the virtue of an exciting new classification system with a purported accuracy of 62.5%. While the number itself is not very high to begin with, the value of that 62.5% begins to diminish further once we evaluate what accuracy really represents. Accuracy is defined as
(number of items correctly classified) / (total number).
Suppose the classes are not equally represented, and rather they are represented in a ratio of 2 to 1. That is, class 1 is the right classification for 2/3rd of the items, and the class 2 is the correct classification for 1/3rd of the items. Consider a degenerate classification system that simply assigns class 1 to all items. The accuracy of that degenerate system is then 67%. And that system does not even do anything!
This simply observation is the reason that there are so many other objective functions – for example, kappa statistic, matthews correlation coefficient, F1 measure, etc, that are considered so much more appropriate than the “accuracy”. Kappa statistic, for example, compares the accuracy of the system to the accuracy of a random system.
December 23rd, 2013
Another semester at GWU draws to a close, and another algorithms class is now done.
Final Grades Distribution – CS 6212 – Design and Analysis of Algorithms (Graduate) – Fall 2013
November 2nd, 2013
Sales training seminars are full of tips and tricks regarding how to win customer’s trust, how to form life-long relationships and how to best articulate the value of your offering. The best of the best sales masters claim to teach you how to sell ice cubes to an Eskimo and sand to the Saudis. God bless the sales masters.
But even the best sales training programs miss out on one puny little, crucial detail. Successful sales people are the ones that are extremely hard to sell to! A good salesperson is a terrific devil’s advocate and will challenge every statement about the offering and the “crucial” problems it solves, until they completely buy in to the offering and it’s value. That challenge phase may come at the time you are trying to hire a salesperson, or trying to add a product to their portfolio. In that aspect, the successful salespeople are watching out for the customers even before they have joined your company or your team!
Due to the same devil’s advocate nature, good salespeople have typically rehearsed many possible objections to the offering and are well qualified to address them by pointing out the core value of the offering, not just by associating with a customer or mimicking a customer.
So, as it turns out, yes, while you may be able to sell ice cubes to an Eskimo, you are going to have a mighty hard time selling the idea of “selling ice cubes to an Eskimo” to a salesperson. She will likely tell you to just give the Eskimo a drink.