The homonym problem

I posted to Yahoo Answers the following question:

Why do search engines have such difficulties with homonyms?

For example - asking for spider identification (meaning: tracing if Google entered your site) retrieves a table with brown spiders.

In a few minutes I got the following interesting Answers:

crythsania
21 minutes ago
Most search engines use the Boolean method meaning you can use words like OR AND NOT. Three litle words but they make a big difference.
and just a heads up...when your searching online about the coding that sites like Google leave when they search your site for updates refer to it spider-bots and it weeds out a lot of useless information on arachnids.

Jockey
21 minutes ago
I don't know what you are talking about!!!!!

Wise_Elder
17 minutes ago
Search engines unfortunately still act more computer like than we would prefer. Their ranking algorithms are calculated on words and numbers and not the intuition of a human. In order to get what you want out of a search engine, you have to ask the right questions. We have to take as much broadness out of each term that we can and clarify as much as possible.
If you search on a broad term like "spider identification", it will not realize what you are trying to find any more easily than if you had said that exact phrase to a librarian. Until you clarify, it can only assume what you are looking for.
Searching for "search engine spider identification" will yield much better results for you than "spider identification" at Google.

d291173
15 minutes ago
They have these problems because they only search on the word, without context. It's not that big of an inconvenience when you consider how long it would take a person, who would have the benefit of context, to find the same information.