Adding more than one article to the same keyword

[batman]

First of all why would want to do it anyway. If you have some updated information then just add it to the old article of yours. A new article means new page and new url which means you have to rank it form scratch all over again. In some cases it may happen though as for example an article which is sharing the top list of something of this year, so the next year you can post another article of that list updated for the next year. But still many webmasters just update the present list and just change the year. As, it helps to get rank faster.