Internal search engine requires a lot of testing

What I am trying to say here is that any internal search engine requires a lot of testing. And not only for keywords but also additional tests for speed. Has it ever happened to you, when you visit a website, type a keyword in the on-site search text field and then wait forever? If you are persistent, you would try to do this a couple more times and in the end get sign like "the search item was not found". Sometimes it gets even worse - you are presented with an error page or this "search" simply crashes your browser.

If you really feel that you need an internal search engine, it should have for the start the following characteristics. First of all, your search engine should be able to clearly visible on the site, understand all possible misspelings and produce results even if you typed them all in capital letters (in other words, no case sensitivity, please). Don’t go over 20 search results, if you think that this may slow down your web server.

The greatest turn-off for visitors is the sign "no results found", so your search engine should be capable of producing some suggestions, links to additional searches and the like. If the results are produced, they should not be cryptic, but clear as water with the closest results coming first.

I can go on with the suggestions forever, but mentioned above points are necessary for any basic on-site search engine. If you feel, that you can not provide these features for your visitors, maybe you will be better off without an internal search engine.