Multiple-choice questions test nothing but passive-recognition knowledge, not active usable knowledge. Knowing something means the power to summon up facts and their significance in the right relations. Mechanical testing does not foster this power. It is one thing to pick out Valley Forge, not Dobbs Ferry or Little Rock, as the place where George Washington made his winter quarters; it is another, first, to think of Valley Forge and then to say why he chose it rather than Philadelphia, where it was warmer.
Multiple-choice tests, whether of fact or skill, break up the unity of knowledge and isolate the pieces; nothing follows on anything else, and a student's mind must keep jumping. True testing elicits the pattern already learned; an essay examination reinforces pattern-making. Ability shows itself not in the number of accurate "hits" but the extent, coherence, and verbal accuracy of each whole answer. Science and math consist of similar clusters of thought, and, in all subjects, to compose organized statements requires full-blown thinking. Objective tests ask only for sorting.
__ Jacques Barzun, from the essay "The Tyranny of Testing"