I find this endlessly frustrating. Often it trails off with an ellipse, leaving me curious as to the conclusion of the sentence, and then when I go to the page it is nowhere to be found.
Agreed. This happens to me all the freaking time, if I could just expand the google snippet and see the end of the sentence or the entire paragraph I would have what I need, but on the linked page itself nothing even remotely close to it.
Exactly!
Is it possible that the text is on a different page on the same site? I mean, I wouldn’t know, because I’ve never been able to find it by clicking around.
A few times this has happened to me, I’ve found that the text is there if you go to the cached page instead of the live one. That suggests that the page content has very recently changed.
I’ve wondered this myself. My guess is the page could have been edited after it was originally scanned by the search engine or the words are imbedded and not shown. But if it’s a specific quote I’d have to say it was edited after being linked.
Or the page is dynamically generated, and will produce different content for different requesters. One problem with almost all crawlers, including the popular search engine crawlers, is that they don’t return cookies set by the site, and thus lose any context which would be maintained in cookies for a user following the links about. In particular, for sites using PHP or J2EE or other app servers they do not return the session cookie such engines typically use to maintain a session on the server side, so each request from the crawler generates a new session.
Another biggie these days is that your typical crawler does not exercise the javascript on a page. What the search engine sees may be some boiler plate “no javascript” text which will be replaced via script for most real users.
I used to mainly use a desktop computer, and would look at the cached version. But now I do the vast majority of my browsing on an iPad, and no longer see the option to look at the cached page.
The text shown beneath the link on a google search result may be the contents of the Meta Description tag - in the HTML Head, it look s like this
<meta name=“description” content=“this is a description of the content on this page”/>
That could be, but then there would be some very strange things in meta tags.
I once looked at the code for a website and found that a person (or maybe their software) had entered literally thousands of words in their meta tags, some of which was copy/pasted from competitors’ websites. So I don’t think I’d be surprised by anything.
That shouldn’t affect things anymore. It was a technique called keyword stuffing, but Google got wise to it and nowadays they don’t even read the keyword meta tags anymore.
I encounter this most often on blogroll pages, where what Google has spotted and cached has long since rolled down or off the page.
I take it as a sign not to go to blogs for information, and wish Goojabot was smart enough to recognize information context better.
What Google could do to make this easier is put back the Cached link so you can see what the heck they indexed. There is still a way to get to the cached page, I discovered it accidentally last week, but I forget what it was. 
If you use Greasemonkey, there’s this
http://userscripts.org/scripts/show/114455