internetheaven - 8:44 am on Apr 1, 2010 (gmt 0)
A high rate of change on a page sends a poor quality signal.
Whilst I totally agree with tedster's comments, I don't think he was harsh enough on the instigating statement. It needs to be made very clear to newbies that fresh pages DO NOT send "poor quality" signals.
Changing the text, title, linking structure etc. can change ranking ... obviously! Google sometimes heavily drops pages that make important changes for a period but the reasons are nothing to do with "poor quality".
WebmasterWorld forum pages change every few minutes, it's rankings seem to be doing fine.