What makes a good curriculum?

Bismillah, alhamdulillah : In the name of God, with gratitude and praise for Him

With the increasing use of the internet in education, what concerns me a lot are teachers who ask students to 'research' a particular topic on the internet. Initially it sounds quite impressive. But a few moments of thought and a few days of experience reveal two fundamental problems: time & security - this post dwells on the former.