Comments on: The Patent System is a Hashtable without a Hash Function

By: Trademarks as Symbolic Links | The Technology Liberation Front

Trademarks as Symbolic Links | The Technology Liberation Front — Sat, 21 Feb 2009 17:32:01 +0000

[...] I said in my last post, Lindberg uses a number of computer metaphors to explain legal concepts. Here’s one I thought [...]

By: Recent Links Tagged With "function" - JabberTags

Recent Links Tagged With "function" - JabberTags — Wed, 31 Dec 2008 14:33:45 +0000

[...] by Trueneutral on Sun 21-12-2008 jQuery create a client-side MVC Saved by kgl on Wed 17-12-2008 The Patent System is a Hashtable without a Hash Function Saved by stewymac07 on Wed 17-12-2008 the “Fold” function Saved by alasdairw on Sat [...]

By: Richard Bennett

Richard Bennett — Fri, 29 Aug 2008 01:59:46 +0000

Yes, we all know the patent system is all screwed up. What we need are constructive suggestions for fixing it.

By: Tim Lee

Tim Lee — Fri, 29 Aug 2008 00:57:41 +0000

It's not a fool-proof system.

That's quite an understatement.

By: Richard Bennett

Richard Bennett — Thu, 28 Aug 2008 23:32:16 +0000

If what you said were true, there would be no new patents, Tim.

What actually happens is that people search the patent data base using a variety of terms, find close matches, and ensure that their patent doesn't infringe by carefully distinguishing it. If you read any patents, you'll no doubt notice a list of similar patents and the explanation of why the patent in question is different. It's not a fool-proof system, but people seem to handle it.

So rather than there being no "hash function" there are several.

By: Richard Bennett

Richard Bennett — Thu, 28 Aug 2008 21:59:46 +0000

Yes, we all know the patent system is all screwed up. What we need are constructive suggestions for fixing it.

By: Tim Lee

Tim Lee — Thu, 28 Aug 2008 20:57:41 +0000

It's not a fool-proof system.

That's quite an understatement.

By: Richard Bennett

Richard Bennett — Thu, 28 Aug 2008 19:32:16 +0000

By: Tim Lee

Tim Lee — Thu, 28 Aug 2008 12:39:34 +0000

The point is that I never claimed that there are no patent search engines. Rather, I was claiming that for any given technology, there's no straightforward way to determine which patents that technology might infringe other than reading all the patents in that technology class. A search engine doesn't help because there's no way to generate a list of search terms that will turn up all relevant patents.

Also, the function might not be strictly O(1), but with a well-designed hashtable the average lookup time is basically independent of the number of elements. In any event, this doesn't really change my point. Substitute another data structure with constant-time lookups if you like.

By: Richard Bennett

Richard Bennett — Thu, 28 Aug 2008 03:02:11 +0000

Right, you used the term "hash function" when you were talking about searching a hash table search function. You used the term incorrectly, but I didn't call you on it and gave you the benefit of the doubt. And BTW, hash tables don't guarantee lookup time, because you can have hash collisions. There are other data structures, such as Patricia Tries, that do provide bounded lookup times; use use them for things like IP and MAC addresses.

Don't be so picky.

By: Tim Lee

Tim Lee — Thu, 28 Aug 2008 01:45:58 +0000

Um, the word “search” doesn't appear in my post.

By: Richard Bennett

Richard Bennett — Thu, 28 Aug 2008 00:55:18 +0000

Tim made the claim that there's no search function for patents, but clearly there are several: Google patents, the USPTO has a free one, and firms like MicroPatent have some that you can pay for. Any law firm that files patents will have a MicroPatent account, or something equivalent, if they're competent. So Tim's claim is false.

Now we can have an interesting discussion about improving the searchability of patents if you want, but let's get over the idea that the Patent DB isn't searchable at all.

By: Aaron Massey

Aaron Massey — Thu, 28 Aug 2008 00:22:22 +0000

Seriously? This is supposed to be easier than Google? Honestly, I think Google's engine is better and more accurate. Of course, if you're talking about the tools that expensive lawyers use, then you're pretty much already in a different garage than the one in which most software engineers tinker.

Though, I do wish you were right about the existence of software patents. (Business method patents should probably also disappear for that matter.) I kinda like Ben Klemens' proposals, but we're certainly not there yet.

By: Tim Lee

Tim Lee — Thu, 28 Aug 2008 00:06:57 +0000

Sometimes I wonder if you're trolling us deliberately. How exactly would a small firm's patent lawyer come up with the list of search terms that will generate a list of all potentially-infringing patents? Remember that even a small software company will have thousands of lines of code, each of which could potentially be infringing.

By: Richard Bennett

Richard Bennett — Wed, 27 Aug 2008 23:10:13 +0000

Apparently you dudes are unaware of the fact that modern high-tech tools exist that make it easy to search the on-line patent database. It's kinda like this "Google" thing that searches web sites, only easier because people write patents in technical language.

But there's no such thing as a "software patent" anyhow, just a lot of computer and electronics patents. But keep searching for that silver bulliet, you may find it one day.

By: Aaron Massey

Aaron Massey — Wed, 27 Aug 2008 21:58:31 +0000

But even setting that point aside, Lindberg’s analogy provides a helpful analogy to explain why patents are a bad fit for the software industry: it’s like implementing memoization using a lookup table without a hash function.

To me the more apt memoization analogy to the patent system focuses on the overlapping subproblems that you hinted at with the Fibonacci sequence example. Essentially, the patent system attempts to use a dynamic programing technique to speed-up innovation. The core problem is that the 20 intervening years during which the patent is valid makes whatever subproblem the patent solved worthless. As you mentioned, there are essentially no valuable software patents from the 1980's. Thus, no one would have a use for these patents irrespective of their ability to perform a lookup. I think this gets more to the core of why software patents really hurt innovation in software rather than the lookup concern.

Although, the lookup concerns are secondary in my mind, they are certainly important. For example, consider the situation that would happen if software patents were only valid for three years. Some of the subproblems those patents solved would still be relevant and important. This means that being able to find a fast solution to those subproblems would be useful. However, without being able to perform an easy lookup the software industry wouldn't be able to make use of any valuable solutions to subproblems with which they may be dealing. Thus, even if the core problem with the patent system didn't exist, the lookup concerns you mentioned would still render current patent system as useless.

This also fits with your discussion of the pharmaceutical industry. They actually benefit from the patent system not simply because they can perform a reasonable lookup, but also because they can potentially still make use of the solutions to subproblems they find to solve larger problems.

By: mlinksva

mlinksva — Wed, 27 Aug 2008 19:43:23 +0000

Regardless of lookup costs, there's a more fundamental problem with

"The patent system acts like a problem cache, storing the solutions to specific problems for later recall."

First there is the implication that solutions would not be stored (ie every time a problem is faced a solution would have to be found anew by the entity facing the problem) in absence of a patent system, which seems absurd.

Second, there is the implication that the content of patents (which are after all what is stored and looked up by the system) contain solutions in a form actually useful to people who have problems, which also seems absurd, though admittedly I know nothing about pharma development practice.

So, in any field, does the patent system actually serve as a solution lookup mechanism for practitioners (and not merely for the purpose of finding out whether a potential solution is patented!)?