The “reducing phosphorus” formative assessment (FA) targets the benefits, costs, and risks of transforming matter. The chemical of interest in this task is phosphorus, which causes algal blooms when the concentrations in waterways are too high. The major question of chemical thinking addressed is “How can the effects of using phosphorus be controlled?”
In the FA task, students use the 
How to Reduce Nutrient Pollution to guide their activity. This task asks students to summarize the two main ideas (where phosphorus comes from and how it gets into waterways) and then use that information to make predictions about (1) how much runoff would occur in a particular place, and (2) how much phosphorus might be contributed to nearby waterways from a particular place (locations A and B). Finally, students are asked to imagine ways that people might be able to reduce the amount of extra phosphorus in our waterways. Students were given one 50-minute class period to work together and were allowed to take it home to finish, if needed.
Note: This task assumes students have enough background knowledge or prior exposure to answer the first two questions relatively quickly. This is not a task for introducing these concepts, but for pushing students to connect their knowledge to a real-world problem.
This FA task was tested with students in 6th grade. The students in this class were English Language Development (ELD) level 1s and 2s, and all students’ native language was Spanish. The students were in a K-8 school in a public, urban district, where about 90% of the students qualify for free lunch. There are large numbers of English language learners (ELLs) and formerly limited English proficient (FLEP) students in the building.
Before engaging in the task of this FA, the students had just reviewed what they learned at the beginning of the year about nutrient pollution, including algae and algal blooms, sources of phosphorus, and its role in causing algal blooms, previous and impervious land cover and its effect on runoff, and land cover in different landscapes. Members of the class had presented these ideas as review the previous day, so the first page of the FA was familiar to them. Following the FA, the students used their ideas about how to reduce phosphorus pollution in a two-week long final project in which they investigated several types of green infrastructure, and then made a recommendation for an installation in our schoolyard.
Teaching reflections
Most students seemed to be able to cite the sources of phosphorus that we learned in class, but it didn’t seem to me that they had a very good sense of which sources of phosphorus were more problematic than others. They did seem to have a good understanding of infiltration and runoff, although I would have liked more specific descriptions of those and the connection to impervious landscape.
For my next use of this assessment, I need to clarify the two instances of the question “How much phosphorus would you expect to be on the ground…?” I am seeing students focusing on the phosphorus that gets carried into the earth via infiltrating water and calling that “lots of phosphorus” rather than focusing on how much phosphorus is contributed to the nearby waterways from that point. I am not certain how exactly to clarify that, maybe it needs a discussion clarification, rather than making the written question too complex, but they aren’t hearing the question I want to ask, so it needs to be clarified.
From the LASW exercise we did on June 7th, my colleague saw two important things that I missed. First, she noticed that all of my students were using appropriate content vocabulary, which is a big deal for ELD 1s and 2s. Second, she wondered whether students were aware of the connection between phosphorus and algal blooms. I believe from discussions in class the day before that they are, but it wouldn’t hurt to add one more quick question at the beginning to be sure everyone is on the same page.
Examples of student work
Morado's Responses
| Questions | Morado's responses [English spelling corrections are shown in brackets] |
Teacher's feedback [other than suggestions made by teacher of Engllish grammar corrections] |
|---|---|---|
| What do you know about where phosphorus comes from? | From the feces of the animals. Exhaust from the leaf. | Which one produces more phosphorus? Which one produces less? |
| What do you know about how phosphorus gets into our waterways and causes algal blooms? | When rains a long [lot] and the runoff moves to the ocean. | |
| How much phosphorus would you expect to be on the ground at point A? Why? | Some phosphorus because will get into the ground in infriltration [infiltration]. | "On the ground" = arriba, en la superficie, no adentro. How much phosphorus is produced here? |
| What would you expect to happen to the phosphorus on the ground at point A? Why? | It will get to the land. | (Circled "infiltration" in previous part and drew arrow to this part.) Why? |
| How much phosphorus would you expect to be on the ground at point B? Why? | A long [lot] because there is too much houses and probably cars too. | What is the connection between these things and phosphorus? |
| What would you expect to happen to the phosphorus on the ground at point B? Why? | It will move to the river. | because...? |
|
What are some things that people could do to reduce nutrient pollution, specifically phosphorus in our water? Think about things individual people could do, things people could build or change about how they build, and any other idea you think might work. Describe at least 2 ideas and why you think they might work. You might allso want to draw a diagram. |
1. Idea is have more pervius [pervious] mantient [maintain] the pervius [pervious] with not build a long of constructions and planting more plants take car [care] of the nature. 2. Use mechanic [mechanical = non-gasoline] cars, specificly [specifically] it noke [doesn't make] exhaust gases in any way. It will work because it will not make esouste [exhaust] wich [which] causes the phosphorus. |
Mechanic: What do you mean by this? Nice! |
Dambi's Responses
| Questions | Dambi's responses [English spelling corrections are shown in brackets] |
Teacher's feedback [other than suggestions made by teacher of Engllish grammar corrections] |
|---|---|---|
| What do you know about where phosphorus comes from? | I think that the phosphorus comes from the feces, exhaust gases and the exhaust of the fabrics [factories]. |
Fabrics = telas Factories = fábricas |
| What do you know about how phosphorus gets into our waterways and causes algal blooms? | I think it when it rains so the phosphorus fall to the rivers, tree, or something closed [close]. |
Fall: do you mean "explain"? ¿Quieres decir cerca? (nearby or close) |
| How much phosphorus would you expect to be on the ground at point A? Why? | I expect that it is like some because the forest it is pervious so it will be infiltration. |
“On the ground” = en la superficie, no adentro. How much phosphorus is produced here? |
| What would you expect to happen to the phosphorus on the ground at point A? Why? | I expect that when it rains the rain it will go in to [into] the ground. | It = the water or the phosphorus? |
| How much phosphorus would you expect to be on the ground at point B? Why? | I expect that in point B are too many houses. | Ok, but how much phosphorus? |
| What would you expect to happen to the phosphorus on the ground at point B? Why? | I expect that in the ground the phosphorous it goes down it call transpiration. |
Down: down to where? How? Transpiration: No, there is no transpiration in this story. |
|
What are some things that people could do to reduce nutrient pollution, specifically phosphorus in our water? Think about things individual people could do, things people could build or change about how they build, and any other idea you think might work. Describe at least 2 ideas and why you think they might work. You might allso want to draw a diagram. |
I think that something that the people need to do is that they are [do] not built [build] houses closed [close] from [to] the river. That they are [do] not go put trash closed [close] to the river or something bad for the rivers. Something that the people can do it is that if they are wanted [want] to built [build] they will try to not do closed [close] from [to] the river or not use materials that produce too many phosphorus. I think that the nutrient pollution it come from the contamination [pollution] from the Earth or something closed like the feces of the dogs, cat or any other animals. The people are did [should] not go and put trash closed [close] to the river because the trash it is a contamination [pollution] for the Earth. That the people did [should] not used [use] too many cars and use something that it [does] not produce too many [so much] contamination [pollution]. |
Close = cerca Closed = cerrado Nice! |
Vampira's Responses
| Questions | Vampira's responses [English spelling corrections are shown in brackets] |
Teacher's feedback [other than suggestions made by teacher of Engllish grammar corrections] |
|---|---|---|
| What do you know about where phosphorus comes from? | The phosphorus came from feces and came from the exhaust gases of the buses and fabrics [factories] etc. |
Fabrics = telas Factories = fábricas Feces/exhaust gases: Which one produces more? |
| What do you know about how phosphorus gets into our waterways and causes algal blooms? | When [it] rain [rains] the phosphorus going [goes] into the river and it [is] going to due [make an] algal bloom. | |
| How much phosphorus would you expect to be on the ground at point A? Why? | I think [there] is maybe some phosphorus there because is [there are] not a lot of them. | Them: of what? |
| What would you expect to happen to the phosphorus on the ground at point A? Why? | That the phosphorus is going to be filtret [filtered] in [into] the ground. | Why filtered? |
| How much phosphorus would you expect to be on the ground at point B? Why? | A lot because [it] is the beign [beginning] of the montain [mountain] and all [the] phosphorus fall [falls] in there. |
Falls: tell more more about this In there: where? |
| What would you expect to happen to the phosphorus on the ground at point B? Why? | (blank) | Does it get filtered here, too? Why or why not? |
|
What are some things that people could do to reduce nutrient pollution, specifically phosphorus in our water? Think about things individual people could do, things people could build or change about how they build, and any other idea you think might work. Describe at least 2 ideas and why you think they might work. You might allso want to draw a diagram. |
I think if we build something in the water like above, the phosphorus can’t going [go] inside of [into] the water. Maybe in the cars [do] not has [make] exhaust gases, or build something to covered [cover] the hall of the cars for the exhaust gases can’t fall in the ground or produce phosphorus. Another idea that the dogs can’t due [do] feces in the ground, or if the dogs due, that the person can recollet the feces of the ground and this can help for the planet, rivers and ground to not has phosphorus into them. |
above: Above what? In the sky? Hall = what word? Nice! |