"Train up a child in the way he should go and when he is old he will not depart from it." 
Just telling my son to do his homework was woefully inadequate. Worse still was asking "Is your homework done?" and having him always answer "Yes."
A wise homeschooler once said "You do not get what you expect, you get what you inspect."
I have realized I need to not only check the agenda for missing assignments, I have to ask to see the assignments when he thinks they are done. His "Yes, my homework is done" means "It's got enough answers on it to look like I tried...."
He had a straightforward map project.
1. Get all needed supplies: atlas, pencil, pen, eraser, ruler
2. Read all instructions before beginning.
3. Color as instructed after labeling is completed.
4. Keep your work neat.
Then 10 specific tasks involving the locating and identification of 3-10 locations on the map, including how to write them (all caps, underlined, certain color, etc.) It's an easy 100% - all the tasks are there. You just have to read them and do them.
Already he'd tuned out.
Half the instructions had been ignored. It took an hour to "finish" his finished homework, with me coaching him at every turn. He honestly seemed to not know how to use the atlas. My fault? A little. The school's fault? A little. Andrew's fault? A little.
Common sense? It's not common. It's a learned skill.
Telling is NOT training. Training is checking, re-checking, coaching, clarifying, inspecting, re-showing, re-inspecting, etc. (lather, rinse, repeat)