Can article summaries be considered duplicate content?

[Coco99]

We have a website with a large number of original content (articles) and we would like to make summaries out of them. The idea is to pick 4 or 5 phrases from the articles and make summaries with them and link to the full article.

We are a bit afraid of being penalized by Google for duplicate content because the phrases are going to be exactly the same. Is it going to be considered duplicate content by Google.

The summaries will be only 15 to 20% of the size of the full articles.

[tedster]

First, the risk is only having one of the urls filtered out of the search results, and that's not a penalty. But what you describe doesn't sound like it would be a problem. You might do even better by both your users and Google to craft a full sentence or two for a summary, rather than lifting out complete phrases.

[harrysmit]

I will also suggest to rewrite your summary instead of picking up full sentence…. You may use some of your keywords in this short para.

[mattg3]

Also extremely dangerous is to make videos and have the spoken text on your page. Then go to youtube,yahoo, Gvideo publish a short summary of the text there and the Youtube page will be ranked higher and the original text seems to loose its ranking.

What is the original text seems to be defined by siterank.

[sherwoodseo]

Good point mattg3 - YouTube video pages routinely hit PR5, and of course YouTube probably scores high on all the non-PR trust metrics.