Less Wrong is a community blog devoted to refining the art of human rationality. Please visit our About page for more information.

GreedyAlgorithm comments on Worse Than Random - Less Wrong

25 Post author: Eliezer_Yudkowsky 11 November 2008 07:01PM

You are viewing a comment permalink. View the original post to see all comments and the full post content.

Comments (99)

Sort By: Old

You are viewing a single comment's thread.

Comment author: GreedyAlgorithm 12 November 2008 08:28:11PM 1 point [-]

Brian, you want an answer to the real-world situation? Easy. First assume you have a source of inputs that is not antagonistic, as discussed. Then measure which deterministic pivot-choice algorithms would work best on large samples of the inputs, and use the best. Median-of-three is a great pivot choosing algorithm in practice, we've found. If your source of inputs is narrower than "whatever people anywhere using my ubergeneral sort utility will input" then you may be able to do better. For example, I regularly build DFAs from language data. Part of this process is a sort. I could implement this plan and possibly find that, I don't know, median of first, last, and about-twenty-percent-of-the-way-in is in general better. I anticipate the effort would not be worth the cost, so I don't, but there you are.

You don't have to *put* constraints on the input, you can just measure them (or guess well!). They're probably already there in real-world situations.