Can I submit the same article to multiple directories? Is this a good practice? is it spam activity or not
Submitting same article in different article directories is a spam activity and nothing. After Panda update, most of the good article directories do not accept content already published or shared in other sites. So, it is not a useful technique.
Its a kind of spamming technique which can create problem for you so better is better is use 1 article only on 1 directory.