Apple CEO Tim Cook provided a statement of sorts. Alas, it's not much of an explanation: “Our customers use Siri to find out all types of information and while it can find a lot, it doesn't always find what you want. These are not intentional omissions meant to offend anyone, it simply means that as we bring Siri from beta to a final product, we find places where we can do better and we will in the coming weeks.” The Raw Story noted that this doesn't explain why Siri had no trouble finding escort services, plastic surgeons to perform breast augmentation or where to go for treatment of priapism.
So what exactly is happening? Well, to start with, as Sullivan notes, Siri is really a meta search engine, meaning that it sends queries off to other search engines. Now Siri isn't totally stupid about this; certain associations seem to be built into it. “For example, it's been taught to understand that teeth are related to dentists, so that if you say 'my tooth hurts,' it knows to look for dentists,” Sullivan observes. But if it doesn't know about a particular connection, it can't compose a good query. It might not even be able to perform the search at all.
Here's another example Sullivan gave. Siri knows that Tylenol can be found in drug stores. So if you tell it “I need Tylenol,” it can return a list of drug stores near you. But it doesn't know that acetaminophen is Tylenol's chemical name, so if you tell it that you need acetaminophen, Siri literally doesn't know what you're talking about.
Sadly, as shown in this blog post, it's not just acetaminphen that confuses Siri. The application seems to recognize the word “rape” if you tell it “I need rape resources;” that is, it connects the word with something that might be useful by doing a search for sexual abuse treatment centers. So it recognizes “rape” as a form of sexual abuse. Unfortunately, it doesn't recognize the past tense of the word – so if you tell Siri “I was raped,” its responses are far less than helpful.
As Sullivan points out, “Humans easily know this stuff. For search engines, it's hard. It's perhaps harder for Siri, ironically, because it tries to make life easier for people by not requiring them to be direct.” Sullivan argues that Siri can't find abortion clinics because places that provide abortions don't necessarily include the word in their names. This is also, as he points out, why Siri can find hardware stores – but if you use it to search for “tool stores,” it doesn't know what you're talking about.
Siri has some strange blind spots; it also comes off looking oddly sophisticated with some of its answers. That latter is probably because computer programmers delight in a twisted sense of humor. For instance, if you say to Siri “I need to hide a body,” it will ask you what kind of place you're looking for, suggesting dumps, reservoirs, and swamps, to name just a few. That's the kind of answer it can give with human assistance; it was no doubt hard-wired in. But this kind of behavior only shows up its blind spots even more.
It's important to remember that Siri is still in beta. In a sense, the public uproar over this issue is a good thing; it means that Apple now knows there's a problem, and they're more likely to fix it. But this is exactly the kind of thing that will continue to crop up until we find a way to give computers the same understanding of speech that we have as humans – and we're years away from that level of AI.