While we truly value the opportunities for children to construct their own knowledge and find their way to answers, we recognize that there are, in fact time when it is time to loan them knowledge. One of my big questions during this investigation of germs has been, "Do I send these children out into the world believing that hand washing is not effective just because we were not able to get to a point of controlling all of our variables enough to get results that match the tons and tons of research that has been done on the topic?" I was especially worried because of the health and safety aspects of this dilemma. We decided that this was the perfect opportunity to share more information with them. We decided to watch Myth Busters “Down and Dirty” episode testing the effectiveness of paper
towel drying vs hand dryers in removing germs during the hand washing process. We decided to show the episode after the work of the children was finished, so that it wouldn't take the wind out of their sails by giving them too many answers. We also felt that showing it towards the end of our investigation would leave them with an increased sense of what great lengths scientists go to in order to control all of the variables necessary to be confident about the results after they had already developed their own understanding for the need to do so. They would see professionals in action with all of the facilities and materials necessary. We felt it would actually help to leave them with an understanding of their path forward on their own scientific journeys, knowing that there were new frontiers for them to conquer.
Here are pieces of their conversation following the episode. It may be a bit hard to follow without all of the background knowledge about our experiments, but I'm sharing so that people can see just how hard the children are thinking about what might be giving them strange and unexpected results.
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What did you notice about the way these scientists worked?
Did you see anything that would help us understand hand
washing better?
Stella: I noticed that you have to be very careful. AND
washing hands IS sanitary! They tested it and it came out clean.
Jude: When they swabbed they put it in a liquid.
Mallory: I think in testing, like if the paper towel
dispenser was dirty enough to make a difference, I think that could help us
because I know that we took out the paper towels but it could have just been
the area AROUND the paper towels that made a difference. And the liquid … I
think our results will turn out different because we didn’t use the liquid. We
just swabbed our hand and swabbed the dish. Maybe the liquid makes sure they
stay on the swab…
Jude: Plus they had a warmer thing. We kept our germs for
like 42 days.
Teacher: Did you notice they kept their dishes in an
incubator?
Arthur: What is an incubator?
Teacher: It keeps things warm.
Sam: Maybe the person who swabs should wear gloves like the
person in Myth Busters did.
Sophia: If you don’t wear gloves, the germs could just
travel from your arm to your hand and down into the petri dish. If you are holding the dish like this, they could
sneak off your hands and into the dish. We should test… we should take a petri
dish and wave it in the air for like 20 seconds and then we should take another
petri dish and just hold it in the air [still] for 20 seconds and see which one
is germier.
Class: Yeah! Do we still have petri dishes?
Mallory: In some of our experiments, there were different
people holding the petri dishes and the swabs and they weren’t wearing gloves.
Teacher: Yeah sometimes three different people were holding
the stuff.
Lila: They would have to be sterile gloves.
Mallory: I know that we opened the swabs on the end without
the cotton, but the germs could have gotten off our hands on that end and
climbed up onto the swabs that way because we didn’t have gloves. I’m really
worried about the gloves now.
Arthur: You know how the petri dishes were closed but they
weren’t taped? And you know how loose the lids were? When they were being
transported, germs from all over could get into the petri dish. It might be
germs from anywhere. Did you get the
petri dishes mailed? The envelop germs might have gotten in.
Teacher: They didn’t grow any germs until we swabbed. If
they have been infected from the envelope, they would have started growing germs
before we put anything in them. ..
Arthur: Then we did something wrong!!!
Stella: What did we do wrong?
Mallory: I KNOW we must have done something wrong because
they had NOTHING growing when they washed their hands with soap. It probably is
the gloves or the liquid.
Arthur: That was a public bathroom.
Dylan: I think maybe they used different soap.
Lila: Like anti-bacterial
Arthur: In public bathrooms there is anti-bacterial soap.
Class member: They didn’t use foam soap… we use foam soap.
Teacher: Did you notice how many people they tested?
Stella: I wrote down, “They make sure they are right!”
Class member: They said 16 people for both ways.
Stella: They make sure they are right!
Mallory: I also wanted to say that they had cleaned the
bathroom or made their own bathroom. It made me feel like the air in our
bathroom might have been dirty.
Teacher: They made it fair. Did you notice how they made the
germs fair on everyone’s hands? We’ve had the discussion before about how to
make sure the germs were fair on the test subjects’ hands. We tried having
people rub their hands together to try to make it even.
Tally: They sprayed this non-harmful germ.
Teacher: They sprayed two times on each person.
Lila: On the front and the back of their hands.
Teacher: That’s how they worked it out. We’ve constantly
been talking about, “What if her hands are more germy than your hands? We can’t
compare them.” They made it fair.
Lila: We should test everyone in the class.
Sam: If you do the pushing the soap yourself or the faucet
yourself, that might be more like a real hand washing experience if you did it
yourself.
Jude: I think I found something that THEY did wrong. I don’t
think they planned the amount of time to swab.
Lila: And they didn’t plan an amount of time to dry their
hands.
Mallory: When they had the people washing their hands, I
heard them count to three.
Teacher: Yeah, I wonder. It is hard to see exactly how they
did it because we don’t see everything. They edit and just show us little snips
of all that happened. It was hard to tell exactly how they did everything.
Lila: Maybe they did plan it out and we just didn’t see.
Teacher: Maybe that could be a questions we add to our list
to ask the expert. “How do you make sure your swabbing is fair?”
