Another Word For It Patrick Durusau on Topic Maps and Semantic Diversity

April 1, 2014

Want to make a great puzzle game?…

Filed under: Combinatorics,Merging — Patrick Durusau @ 7:06 pm

Want to make a great puzzle game? Get inspired by theoretical computer science by Jeremy Kun.

From the post:

Two years ago, Erik Demaine and three other researchers published a fun paper to the arXiv proving that most incarnations of classic nintendo games are NP-hard. This includes almost every Super Mario Brothers, Donkey Kong, and Pokemon title. Back then I wrote a blog post summarizing the technical aspects of their work, and even gave a talk on it to a room full of curious undergraduate math majors.

But while bad tech-writers tend to interpret NP-hard as “really really hard,” the truth is more complicated. It’s really a statement about computational complexity, which has a precise mathematical formulation. Sparing the reader any technical details, here’s what NP-hard implies for practical purposes:

You should abandon hope of designing an algorithm that can solve any instance of your NP-hard problem, but many NP-hard problems have efficient practical “good-enough” solutions.

The very definition of NP-hard means that NP-hard problems need only be hard in the worst case. For illustration, the fact that Pokemon is NP-hard boils down to whether you can navigate a vastly complicated maze of trainers, some of whom are guaranteed to defeat you. It has little to do with the difficulty of the game Pokemon itself, and everything to do with whether you can stretch some subset of the game’s rules to create a really bad worst-case scenario.

So NP-hardness has very little to do with human playability, and it turns out that in practice there are plenty of good algorithms for winning at Super Mario Brothers. They work really well at beating levels designed for humans to play, but we are highly confident that they would fail to win in the worst-case levels we can cook up. Why don’t we know it for a fact? Well that’s the P \ne NP conjecture.

Can we say the same about combinatorial explosion problems? That under some set of assumptions such problems are intractable but that practical solutions do exist?

I mention this because one of the more shallow arguments in favor of a master ontology is that mapping between multiple ontologies (drum roll please), leads to a combinatorial explosion.

True, if you are dumb enough to insist on mapping from every known ontology to every other known ontology in an area, that’s very likely true.

However, if I only map from my ontology to the next ontology known to me, leaving other one to one mappings to others who want them, I am not closer to a combinatorial explosion than creating the mapping to a master ontology.

I must admit my bias in this case because I have no master ontology to sell you.

I prefer that you use a classification, taxonomy, ontology you already know. If it’s all the same to you.

Mapping your classification/taxonomy/ontology to another is something I would be happy to assist with.

PS: Do read Jeremy’s post in full. You will learn a lot and possibly pick up a new hobby.

No Comments

No comments yet.

RSS feed for comments on this post.

Sorry, the comment form is closed at this time.

Powered by WordPress