No I don’t have any evidence concerning the weight that keywords in the
URL play. It is gererally accepted that keywords in the URL have
Ranking weight – how much, no one really knows.

How ever I can offer evidence, and just have, concerning the command
allinurl: and what form of keywords it uses in determining the results
position from the allinurl:keyword command. It is the latter, not the
former that my posts have been discussing.

Just do an allinurl:web design, or any other 2 work phrase that suites
your fancy, and you will quickly see that the results are made up of
the key words web and design seperated by a dash or forward slash or as
a file name or directory by themselves. In most cases you will not see
in the results entries that show the two words together (i.e.
webdesign) in the URL.
A search for
webdesign returns 19,100,00 results
web design returns 28,100,000
“web design” returns 15,100, 000 results.

While these are estimated numbers of pages and may not be correct, they do show that each is considered as seperate terms.

Bob, I would also like to see your evidence. I have tested this theory
and found the exact opposite. To begin with, an allinurl query has
nothing to do with rankings. Searchers do not use an allinurl when
searching. You might, but 99.99% of searchers do not.

If we are talking Google only here, then here are some facts for you.
Test yourself if you like. The bolding of terms is nothing more than a
representative that the word was found. Google DOES NOT use the
description for ranking purposes, though will bold the words found
within the description if used instead of a snippet.

As David said earlier, names in URL’s, folders and filenames actually
have little to no affect in Google anymore. They are bolded in the
SERP’s for display purposes that hopefully the site is about what you
have searched, highlighting some parts of the results for you to make
your choice a little easier without having to read each and every
result word to word.

Again, this is Google. Yahoo and MSN are completely different again.
This is from actual testing I have done, most likely something like
David has also done for himself to find the fact from the fiction.

Next part, hyphens. Google will actually read words within words,
whether hyphenated or not. Google has done so for a long time now
actually, for those that haven’t noticed. You DO NOT need to hyphenate
words within domains for Google to have them read as unique words. For
example, the domain “thedomainisfortestpurposesonly.com”, Google will
actually read any part of any word within that domain. Google will see
that exactly the same as “the-domain-is-for-test-purposes-only.com”. To
a user, the hyphenated version is easier to the eye, though to the
search engine, either is acceptable and read the same for the same
query.

http://forums.searchenginewatch.com/showthread.php?t=1505