Recently I’ve been working hard to really understand the topic of assessment. I was going through the types of validity, wondered about the impact, tried to make connections to the tests at my work and did my best to figure out what the test really measures and if it is enough. I was also reading about various types of assessment and criteria. But something was missing. As usual, if you don’t know something, you cannot specify it to look up; you just feel that there is another piece of the puzzle to be added.
Yesterday I found that missing piece. It was explained in the amazing book “The One World Schoolhouse” by Salman Khan.
He proposed a concept of the Swiss Cheese (the one with lots of holes) and just for this that honoured and honest man deserves to be read by each teacher. Here is the quotation:
Let’s consider a few things about that inevitable test. What constitutes a passing grade? In most classrooms in most schools, students pass with 75 or 80 percent. This is customary. But if you think about it even for a moment, it’s unacceptable if not disastrous. Concepts build on one another. Algebra requires arithmetic. Trigonometry flows from geometry. Calculus and physics call for all of the above. A shaky understanding early on will lead to complete bewilderment later. And yet we blithely give out passing grades for test scores of 75 or 80. For many teachers, it may seem like a kindness or perhaps merely an administrative necessity to pass these marginal students. In effect, though, it is a disservice and a lie. We are telling students they’ve learned something that they really haven’t learned. We wish them well and nudge them ahead to the next, more difficult unit, for which they have not been properly prepared. We are setting them up to fail.
Forgive a glass-half-empty sort of viewpoint, but a mark of 75 percent means you are missing fully one-quarter of what you need to know (and that is assuming it is on a rigorous assessment). Would you set out on a long journey in a car that had three tires? For that matter, would you try to build your dream house on 75 or 80 percent of a foundation?
It’s easy to rail against passing students whose test scores are marginal. But I would press the argument further and say that even a test score of 95 should not be regarded as good enough, as it will inevitably lead to difficulties later on.
Consider: A test score of 95 almost always earns an A, but it also means that 5 percent of some important concept has not been grasped. So when the student moves on to the next concept in the chain, she’s already working with a 5 percent deficit. Even worse, many deficiencies have been masked by tests that have been dumbed down to the point that students can get 100 percent without any real understanding of the underlying concept (they require only formula memorization and pattern matching).
Continuing our progression through another half dozen concepts—which might bring our hypothetical student to, say, Algebra II or Pre-Calc. She’s been a “good” math student all along, but all of a sudden, no matter how much she studies and how good her teacher is, she has trouble comprehending what is happening in class.
How is this possible? She’s gotten A’s. She’s been in the top quintile of her class. And yet her preparation lets her down. Why? The answer is that our student has been a victim of Swiss cheese learning. Though it seems solid from the outside, her education is full of holes.
I can’t agree more with this point. If I knew the answers to the test questions – wouldn’t I have written them firsthand? And if I didn’t the chances are that I just don’t know or don’t understand what I am supposed to. Will doing the test again help me? No. Will the teacher’s comment, that I should come back to certain chapters or units, help me? Maybe. Will it help me if the teacher really turns back to the notion and provides me with materials and helps to grasp the idea itself help me? Yes.
So why don’t we use testing as a stage of a lesson to check understanding? Not the final part, but a regular work to see if everything is going on well. Then missing points won’t make difference in the final points but will allow getting an emergency support for the stuck ones. Then getting 100% will be the question of personality and time. And if sooner or later everyone gets to 100% with the full understanding of the concept, then why do we need those final school-governed exams at all?
I shared this idea with some of my colleagues and got a reply that some students just cannot grasp the idea for now and after a month of hard work 75% in the test seems to be an achievement and we should move forward. We rely on recirculation of material (often poor and not well-staged), that sometime later we again approach the topic with a fresh sight. In reality, we may or may not come back soon. Students are almost certain to forget that half-gotten concept, so we will need to start again. If it’s something like -s for Present Simple or a capital letter for weekdays and months, it may be not just forgotten as a piece of theory, but may also turn into the mistake, following a learner till high levels.
It’s sad that in practice we have to go for low expectations and half-grasped material. The timing is too crucial when we teach in schools, we cannot stop. Moreover, in most cases, we even cannot do regular testing (as it is in my school). And even if we do, we still have no time to do lots of one by one feedback and practice. But I do want to try, at least in a few classes.
So how good is good enough? A perfect score seems to be pretty good; aim high, expect more,