What exactly Shallow content is?

web2.0 & short article is hit by Panda update. google call it Shallow content

http://dotgiri.com/2011/06/08/google-panda-update-2-2-did-google-rolled-it-out-tips-to-recover-from-panda/

then i search about it and this i found
Just because an article is long doesn’t mean there’s more value. Just because an article is short doesn’t mean that it’s shallow. Sometimes long articles are long merely for the sake of it. Sometimes short articles are jam packed with great information and resources

any one tell me What exactly Shallow content is ?

Google again change it algorithm nick name Google Panda.It has bad effect to all sites containing shallow content and duplicate content.Shallow content are contents having small or no description.For example ecommerce sites that have many products with little or no product description that sites can be banned under Google panda.Ideally you want about 250 words of product description for each product. Failing that, shoot for 100 words at a minimum.

I would consider shallow content, content that has none or very little unique parts to it, scraped content, mashup pages, pages with just search results, article spun pages and pages with very little content.

Google is looking for quality unique content. No one knows for sure how many words it takes to not be considered shallow, but if you focus on producing quality content and writing what others will find useful and not stuffing keywords in it, then I believe you will be in good shape.