Inside View

Making the best choice #math

EVERY VALENTINE'S DAY, I open the Journal of Mathematics to read how to make best choices. TL/DR: Take the square root of the choices and discard those from the initial batch.

This process is "an extension of the secretary problem in which the decision maker (DM) sequentially observes up to n applicants whose values are random variables X₁;X₂;...;X_n drawn i.i.d. from a uniform distribution on ½0;1. The DM must select exactly one applicant, cannot recall released applicants, and receives a payoff of x_t, the realization of X_t, for selecting the tth applicant. For each encountered applicant, the DM only learns whether the applicant is the best so far. We prove that the optimal policy dictates skipping the first sqrt(n)-1 applicants, and then selecting the next encountered applicant whose value is a maximum." [1]

Eight More Guardian Tech Sections

IT'S THURSDAY and I'm happy buying the print edition of the Guardian. I get the Guardian on Thursdays because of its standalone technology section. The section will cease publication at the end of the year and I'll be without a major source of trusted information. Perhaps the tech crew will continue publishing online with the Guardian but I'll miss their print presence. I prefer the Techonology Guardian in print format because I can scan the entire section faster when it's sitting under my bag of chips than I can see its content online. Besides, you can't put a bag of chips on top of a Kindle and count on soaking up the vinegar and cooking oil. The Technology Guardian taught me a lot about Irish innovation, through the words of Vic Keegan, Karlin Lillington, Charles Arthur and Tim Radford. In the mid-90s, I religiously read Computimes on Mondays and the Technology Guardian on Thursdays. I learned the tech landscape that way. Computimes wound down before Y2K. A decade later, the Technology Guardian has also let the stage.

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Jack Schofield's Tech Blog.

Charles Arthur's blog.

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