Hi, I've got one site, that has numerous (>300) supplementary results cached for old pages which no longer exist. Does any one know of a way to get these damn things out of the index. I would have hoped that G would dropped them after consistently getting 404 errors, but that seems not to be the case. I suppose I could 301 them to the homepage and eventually they should disappear.
First, I would suggest that you either do the 301s or place an errordoc on your server so that the 404s do not degrade your site efficacy in the eyes of search engines. As far as the "supplemental results" go, there's nothing I'm aware of that will discard or replace them except time itself.
OK, so the next question is: Does the co-op ignore supplementary results. I'm wanting to add this site to the coop, but don't really want the validation hassles that come with having indexed pages that the code can't exist on. 301's will be going in place today.
I have always thought that google will not remove a page from its cache if they get a 404 error, I assume they think it may have been a temporary fault or something. The quickest way I get rid of them is to redirect to the homepage or a page similar to the old one.
A better technique in my view is to 301 them to the sitemap. Make sure its an easy to use an SEO friendly one. This will help in indexing new pages if Google is still following the old links and also if Google decides to use one of your suplimentary results in the SERPs, visitors can find what they need. A sitemap helps both those thing better than the home page if done properly
I'm redirecting them all to a special nolonger.php page. That way I can easily see when they stop getting hit. Be interesting to see how many IBL's end up pointing to that page. It should hopefully mean that the coop will always validate as well