Beginning of August (1st or 2nd), I decided to change the text content on my of my webpage because it was not ranking at all for its keywords (I checked the first 2o result pages of google and it was not there!). I had a read through the body of the article and I wasn’t quite pleased with the text, so I made considerable changes to the article and I would say at least 50% of the content was changed. Now this is a risk that you don’t really want to take because when Google crawls your webpage again, it will find that the content differs significantly from what it was before and this could get you removed completely from the index and unranked for an unknown amount of time.
I took the risk because I couldn’t be worst off (c’mon not ranked among the 1st 20 pages!) and I speculated that my rankings will come back within at least 2 weeks. I checked rankings for the keywords for that page nearly everyday after making the change and today (after nearly 2 weeks), I’m listed on Page 4 of the search results at Position 38.