William: Today we're going to be looking at the zebra mussels population with 20 years of data.
Today's class was working on creating an argument on whether or not the zebra mussels had a positive or negative effect on the Hudson River ecosystem.
Today we're going to use all the stuff that we've gathered as far as evidence.
We're going to be doing the argument tool.
Speaker 2: The NGSS are really meant to be engaging all students at all levels with science phenomena and to think about solving problems. And I definitely feel like we saw evidence of that in William's classroom today.
William: In the beginning of the class, I asked students to do a reading, which provided some additional information on the effect of the zebra mussels, long term on the Hudson River ecosystem. They've already looked at some data provided by the American Museum of Natural History website. The students are writing an argument on if they've had a positive or negative effect on the ecosystem based on their findings.
We hand out a couple argument tools. And we'll go over this and fill it out together before I give you time to get started.
The argument tool itself is a type of graphic organizer where kids can start to process their thinking in preparing for the argument by listing the claims that they can have for both sides of the argument. Weighing those choices and seeing which one they believe has stronger evidence in the forms of data.
So we're going to fill out and we're going to look for evidence from both sides. You guys are allowed to use anything that you've had from the reading, anything that you have in your science notebooks from looking at the website, and we also printed out some of the bar graphs that you can also use as evidence to fill out both sides. You're then going to have to decide on which one you think is best. Okay. You can get to work.
Student: Every time the zebra mussels increase, the copepods went down.
Speaker 2: William's role was about guiding the students. He asked them questions. He was helping them figure out how to make sense of the evidence, in particular. He was really making sure that they understood the data.
William: So now, let's take a look at 1990-2000. So the zebra mussels have now entered the Hudson River ecosystem, correct? Okay. That's the first bar, so put the Z here for zebra mussel.
What is the value of the zebra mussels? Can we put a number on that?
William: We're using this axis.
Student: 140? 100. 1,400?
William: 1,400. What do you say?
Speaker 2: Even though he had already taught a lesson, he noticed that some of the groups might have been struggling with the graph a little bit, so he was helping the group figure out how to make sense of the data and then how to use that data to support a particular claim.
Do you remember what the scientist said about the plants?
Student: Oh yeah. It said that the plants-
Speaker 2: Yeah. Remind us of that.
Student: The uprooted plants, I think they grow?
Speaker 2: And you saw the kids thinking about the ecosystems, applying all the ideas they had been learning about throughout the whole unit.
And why would they grow better if the water is more clear?
Student: Because there's more nutrients.
Speaker 2: Clear water would be more nutrients?
Student: No. Some-
Student: Yeah. More sunlight.
Speaker 2: Bringing up those same ideas again, that spiraling of content, it's not separate discrete pieces of information. We see them tying in lots of ideas in order to make sense of this phenomena that they're observing.
Student: Sunlight and the water make it grow.
Speaker 2: Yeah. They need the sunlight in order to grow. So one of the positive things you could write down ... so I agree with what you said before that it could be positive if it's helping the plants grow.
William: It's interesting to just help facilitate the children in looking at which pieces of evidence they're actually pulling out and which they feel strongly about and creating a valid argument.
Asia: All right, so the phytoplankton started out at about 15 million and that's the population and then when zebra mussels came back about 1,250, they dropped down to about six million and then it just continued to decrease.
William: It changes the way they get the information. They're getting to access the content.
Asia: And again, it continued to decrease as the zebra mussels-
William: Tell me if you can make a relationship between these two things in this graph. Is this-
In this style, because I do have to move around from group to group and answer different questions, I'm more engaged with the students.
And what happens to the chlorophyll?
Student 3: Well, the chlorophyll started ... it really dropped. It decreases a lot.
William: And I like getting into the conversations with the students about the concepts.
When zebra mussels decrease, what happens to [inaudible 00:04:53]?
Student 4 : They decrease even more.
William: So no matter-
Speaker 2: I got to see today in the classroom with students really grappling with the evidence that they were presented with and really thinking about whether or not that evidence supports a particular claim.
William: Everyone has gotten evidence for both sides. Let's hear from some people now that feel they found some strong evidence for ... let's go with claim A.
Student 5: When the zebra mussels first came, they kind of purified the water so that became more clear. So shallow fish, the plants grow more because there's more light in the water. There's more light being put in the water, so there's more plants so that the fish can eat.
William: Does anyone have a reaction? Counter claim, rebuttal? Yes.
Student 3: The zebra mussels were making the fish population decrease because the zebra population were eating the same food that the fish were and that they were eating most of it, so they didn't have enough food for themselves.
William: You were on the positive side or the negative side?
Student 3: Negative.
William: Negative sound. That's interesting.
Instead of going from A to B and having a final decision as yes or having a positive or negative effect on it, we end the class without really saying, "Yes. The teacher is saying there's a positive effect," or "No. This is having a negative effect."
For homework tonight, I want everyone to finish both sides of the argument tool. That means-
When people think about science or the scientific method, they often forget the final part which is sharing the science findings. If you don't do that, you're actually not practicing science. So we're preparing them for conducting an argument and getting into the conversation with them, I think is closing that gap and finishing up that most important piece of science, which is sharing your information, sharing your findings with someone else.
Critique of the rebuttal. What does that mean? Asia?
Asia: In my case, it would be that the zebra mussels supported the ecosystem and basically you have to write down a piece of evidence for that side and explain why it's not really a good piece of evidence.
William: And so I think this helps prepare them. That missing piece that they often leave out in other classes and other teaching styles.
Okay. Everyone pack up. Bring up your books. Make sure you have a rubric to complete your arguments tool and you can keep the graphs.