I want to use noindex, follow meta tag on all bad articles. or deleting bad articles. which is best?. If i delete articles, i get lots not found pages on google webmaster tooll. how to avoid it.
If you are penalized by google because of the bad articles, then deleting them is the best option for you, right now. However if you are changing the complete domain to a new one, then better put those articles in the new domain first and then delete from the original source.