Popping over here per your request on my talk; Gerda, it's not only the phrasing-- the problem we often see at DYK (and that folks everywhere fail to pick up on when they use tools like the duplication detector) is that the entire structure is copied. When the flow and structure matches the source, you can see that text was copy-pasted in, then words just juggled around (which avoids duplication detector tool picking it up). These frequent claims that involve "only a few words" come from people who aren't looking at the structure of the article. You can read the source, read the article, and see that you're looking at the same thing with a few words juggled. If you've addressed that, I'm not concerned for a closer look-- feel free to remove the tag if you're satisfied. SandyGeorgia (Talk) 14:10, 2 February 2012 (UTC)[1]
Again, examine the structure-- not just the words and phrases. Copying the structure is copyvio. See the Plagiarism Dispatch:

Unfortunately, there is no hard and fast rule for how much revision is necessary to avoid plagiarizing. In evaluating copyright concerns, the United States courts adopt a "substantial similarity" test that compares the pattern and sequence of two works, finding such similarity where "the ordinary observer [reading two works], unless he set out to detect the disparities, would be disposed to overlook them, and regard their aesthetic appeal as the same."[17] Even if all of the language is revised, a court may find copyright infringement under the doctrine of "comprehensive non-literal similarity" if "the pattern or sequence of the two works is similar".[18] Likewise, plagiarism may exist if readers comparing the two works would come away with a sense that one is copied from or too heavily based on another.

I read the source from Lonehurst Cabin, then read the article, and there was no doubt I was reading the same work-- then I engaged Duplication detector to pick up specific instances, but if the structure is copied even if words are juggled, it could still be a problem. SandyGeorgia (Talk) 14:18, 2 February 2012 (UTC)[2]