Recycling Content

Using old content for a new site - how much do i need to edit?

[tomthumb2000]

I have a large informational site about widgets. I want to try and see if google responds to a themed site about blue widgets.

So i'm taking all my articles about blue widgets from the old site and putting them on the new site with some changes.

My question is: how major do those changes need to be and how can i know if i have edited the articles enough to stand out as new, unique content?

If this works i plan to have new sites on green widgets, yellow widgets etc...

[engine]

I'm not sure there is a figure that can be put on this.

Here's a previous (short) discussion on this topic.
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