Google messages & penalties

[gfiedel]

I just read the following comment in a response to someone else's question. The Responer is an SEOMoz Authority whose opinion I respect and have learned from (not sure if it's cool to mention names in a question) and it spurred my curiosity:

"...Generally you will receive a warning from Google before your site is penalized, unless you are talking about just specific keywords."

This is something I have been wondering about in relation to my own sudden  ranking drop for 2 specific keywords as I did not receive any warnings or notices. I have been proceeding as if I had over used these keywords on my Home page due to an initial lesser drop, but identifying the cause for the huge drop still seems useful for a number of reasons. Can anyone explain this further?

[SVmedia]

If you receive a warning in Google Webmaster tools, that's seen as a manual penalty.  If you lose rank for a few keyword terms it might be an "algorithmic" penalty - which just means that Google no likey.  These types of penalties are difficult to assess.

Usually key phrases would be penalized because of unnatural patterns in anchor text.  I would look at your anchor text distribution in open site explorer and see what you've got going on.

[gfiedel]

Thanks Colin. Your response clarifies "manual" warnings. I have wondered about the difference between "manual" penalties and receiving an email warning in GWT. I understand you to be saying those are one and the same. Yes?

I am still hoping to learn more about the methods by which a couple of specific keywords might be penalized if no warning was received.

I know this specific keyword issue is not related to inbound links in this case.