Keep it Under Control of Error

On my second year of working as a guide in a Montessori class, I had a 5-year-old boy who, his parents told us, was diagnosed with what was then called PDD-NOS. For the first few days of school, every time he was about to have his snacks, he would cry, make high-pitched sounds, pound the table. At first we thought maybe he didn’t want to eat (though he was the one who got his snack bag) because he was just there doing these in front of his unopened snacks–so we’d invite him to work–but that didn’t work. So we observed and experimented some more until one day I saw it… So one day while he was crying and pounding in front of his snack bag; I sat beside him with a marker and scissors, I took his pack of crackers, then with the marker I drew a broken line along the top of the plastic and I showed him how he can cut along the broken lines so he can open his snack. And I swear to you that did it–since then he stopped crying and pounding during snacks. Eventually it came to a point when we didn’t have to draw broken lines anymore–I just told him to see if he can imagine the broken lines and cut.

That simple broken line–that was a kind of, what we call in Montessori, Control of Error–a built-in means for the child to do the process independently and/or to check and correct his own work. It is one of my favorite Montessori tools and one of the ways I use it is to help me keep my calm during times when I’m about to lose it.


It was happening again and again all throughout the day–my daughter was getting water for painting from the faucet and the water from her cup was spilling on the floor. The first few times, it was easy to give my usual responses “Is it a problem that can be fixed” or “It’s a problem that can be fixed” as my daughter gets the mop or a rag to wipe the floor. But it kept on happening. I was needing more conscious effort to keep my calm as I observed–and I realized that the cup she was using didn’t have a Control of Error (it got erased after several washing). So I took a strip of tape and wrapped it around the cup and drew a broken line which indicates up to where the water goes (I say, “We can put water up to the line”).

When there’s a situation where I feel there’s a need for constant correction, I try try try to keep my calm by thinking about Control of Error–is there something I can add to the material or the process so that the child can do it independently and successfully?

Controls of Error (like that line on the glass or that label 3 on the bottle of our Maam and Moms tempera paints) help us make the material and environment work for us–when applicable, they’re the ones communicating limits and boundaries to the child; instead of us doing that work all the time and running the risk of losing our calm along the way. Let’s keep things–most importantly ourselves–under control by using Control of Error. Broken lines, small labels–these Controls of Error–sometimes that’s all it takes–these little thoughtful additions make a profound difference–and they become so much more–just like those simple broken lines I drew on the cracker packs of that 5-year-old boy in my class years ago were so much more.


P.S. I wonder what Control of Error will work for the cat.

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