While SAT achievement tests purport to measure the extent of competence within a given subject matter area broadly defined, all of this is backward in that we must first decide the topics for consideration and then the methods that the nature of the content will require. To think that the practices taken from generations ago if not centuries if not millennia are the answer really won't do, no matter what the old professor with his tone of certainty might declare. I have a strange feeling that nobody actually knows this answer, for in a world changing as fast as ours, the ever conservative schooling institution has no chance of keeping pace. In modern times, we just can't keep up.
Perhaps we could start to address the problem with the unthinkable: that when someone is 70 he or she should retire - not from life, but from teaching. Gulp.
Here's my suggestion. We take one month in the summer and those who volunteer (that means we don't have to say yes, but we do get paid if we do) develop a module for Essential Study. Then we try them out as special topic 5 week courses. Once clarified, rewritten, modified over time, these can be website posted for possible use copyright free, nationwide. A certain number of these can be offered each year, but, and here's the kicker, each student maps his or her own course of study.
To Plato's curriculum [the word derivation suggests a pre-cut path through a field designed to make it easier for a cart to travel] has now been added student choice. For which of us want to travel someone else's path? It's hard enough to find and to deal with our own. Students simply must get acquainted with the concept of active choice. Once they do, motivation will have very different colors and maturation will be substantively propelled. There's something compelling about electives in a democracy.