CER – Developing Structures

Evidence. It’s challenging for my 7th graders to keep coming back to evidence. Personally, I’ve struggled finding the right scaffolds for students to have them put together investigations and share their thinking. The following is my latest installment based upon some past work with Paul Andersen (@paulandersen) and continual shifts in thinking towards NGSS practices. In the end, student goals are to have strong conversations about their investigations, clearly model design, display key evidence and conceptually model their ideas.

Screen Shot 2018-05-07 at 4.22.09 PM

(Link to above document)

The structure above is used at the end of an investigation though students need to show their experimental design. (A topic for a different time – how much emphasis are people putting on the physical writing of a procedure versus setting up the experimental design and then moving forward?)

Experimental Design: In the experimental design, students create a model that shows their set-up with the independent, dependent and controlled variables clearly indicated. Below are a couple of student examples for an investigation where the mass of a dynamic cart was varied as students examined change in velocity with constant force or an applied force was varied.

What I like:

  • The visual nature of setting up an investigation through a model.
  • Highlighting the variables. My students are not always 100% confident on independent, dependent and controlled variables. This color connection makes them again talk about the variables. They also quickly realize if parts are missing from their model.
  • There is a focus on the experimental set-up. Students are talking about the parts of the investigation they are working with.

What I wonder:

  • For seventh graders, is this good enough? In the past, I’ve spent a lot of time word smithing on procedures and I’m not sure that that is necessarily time well spent. What do I really want? I would like students to have a strong foundation in designing investigations that focus on a relationship between an independent and dependent variable. I would like students to truly grasp the need to keep all other items controlled.
  • How can I mix in a strong foundation of procedure-type vocabulary that students then show on the model?
  • What can be done to improve on the current model? Does more need to be done regarding the independent / dependent variable relationship? What about the controlled variables – how do the key ones really stand out?
  • Multiple Trials – One group wrote to repeat for every trial though they did not indicate how many trials would be necessary. Maybe I should make this more specific.

Data: Once the set-up is ironed out, students move to collecting data. Organized data tables are challenging to set-up! We eventually get data tables constructed in a spreadsheet and students begin collecting. This post is more related to the workup of ideas so let’s move to the display of evidence.

What I like:

  • Paul Andersen was the one that led me to showing all of the data collected in trials on a graph. In the past, students showed the average only but a lot of information was lost. We now have conversations about the range of data and the confidence level of groups in whether or not they have a strong data set.
  • The graph is another place where we check in on independent and dependent variables.
  • Physics! We got reproducible data almost across the board and it really does make a difference.
  • Working up the data into a graphical display and then having students write a claim.

What I wonder:

  • Students are doing more with data in spreadsheets though get really turned around when it gets to graphing with the software. I like the investment of time to go into discussing the data instead of physically graphing but I don’t have a good solution yet for graphical displays. (I’m toying with Excel/gSheets, Desmos and CODAPany others?)

Conceptual Model of Claim: In support of the claim that student groups generate based upon their data, I’m working with the idea of a model to explain ideas. Evidence is shown on the graph, so the focus here is more in showing the big idea of the claim. This is definitely a work in progress and in need of refinement.

What I like:

  • Students are returning to the relationship of the independent and dependent variables.
  • By having this piece not focus on numbers, students talk more about representing their ideas.
  • A focus is placed upon the claim being a representation of the data. Our conversations were around what patterns are in the data and how can this be shown.

What I wonder:

  • Dot diagrams were provided as a way for students to model their thoughts. In other areas, is it good for groups to have similar models for better comparison or better to have groups represent in any way they like?
  • What additional description should accompany the conceptual model. Is the claim and the model enough?
  • Many more thoughts running around…

Reasoning – With my 7th graders, I’m finding that more structure is still a good idea when writing a claim. We return to the relationship of the independent to dependent variable and I want to see students including specific information from their trials of what was changed and what was measured. My focus has been on developing a solid reliance on evidence that I hope can then be used to eventually link to strong reasoning.


Making, Baking and Taking Samples

Geological-map-of-China Site Key

During earlier days working in an engineering consulting firm, I remember my geologist buddies heading out for days at time to drill sites. Some days, I envied them as they spent glorious spring days outside while I modeled or wrote reports back in the office. Other days, I enjoyed the warmth of the building as they toiled under the wet and cold conditions of a Pacific Northwest winter. My students are budding geologists and we tried to simulate a bit of the sampling experience.

The above map provides a basic overview rock in China. Eight different sites were overlaid. Sites were selected next to cities so that students could reference names as they worked. I was also curious how a wide spread set of “top layers” would work out. Would it allow me to differentiate groups? Would there be more conversations with a wider number of sites?

To begin the project, students joined a group that, depending on the numbers in the class, ranged from three to five students. As such, out of the eight sites on the map of China, student groups represented four or five. They did not see the overview map at the beginning. Instead, students were given a map of China with a box at their site and a zoomed in version of their site (the boxed area). As a group, they were asked to decide how the site would be split up and who would be responsible for each portion.

This year, I am experimenting with the line between group and individual work and trying to find a good balance. As individuals, I want each student to be engaged and have the opportunity to process on their own. As a group member, I want each student to work on collaboration and promoting ideas. In this task, once the site was split up and discussed, each student had to design his or her own cupcake of their portion of the site.


Stepping out of the classroom always provides interesting views into the picture of who my students are – some were quite comfortable working around in a kitchen space while others were almost paralyzed at layering their cupcakes. In the end, the cupcakes were all put together and baked. Five minutes passed as the students sat mesmerized in front of the oven watching baking bread. Hmmm – who knew it was so fascinating.


When cooked and cooled, the samples were iced to cover the top layer and then students were given an unknown sample. Their group’s task was to know identify which site was represented by the unknown group of cupcakes. Each student was allowed three core samples – using a straw they drilled down into the cupcake. Core samples were sketched and students asked to draw the cross section of their site.


With 12 to 15 core samples per group, students began processing information. At this stage, I felt that I did not do a great job in guiding students. Partly, I was curious in how they would work with the wide amount of data. Each sample had the possibility of four layers and some were more mixed up. This gives 50 or so “pieces” of evidence though for this task, students really only needed to look at the top layer of their samples. Some groups figured this out quickly and others took time but got there. What was not done well was how students represented this information. I feel that I need a bit more work in using images to capture data.


It’s great when spontaneous argument begins in class. As groups narrowed down their sites, I realized that some groups had picked the same site. I put these groups together to hash it out. Awesome, wonderful conversations ensued. Unfortunately, this was not replicated in the other three classes. Looking back, I realize that the spread of initial sites offered to much variety. I want the argumentation to come out and as such need to have sites that will hopefully lead students to a state where they need to really work with evidence and convince others of their ideas.


Long post note: I hope I will remember to look back over this post if this project is done in the future. Hence, a broad overview. Modifications:

  • Focusing on sites that are more similar in nature may also help with the batter issue. A few classes had shortages though not of the same color.
  • Sprinkles as fossils did not work out – the sprinkles disappeared while baking.
  • Straws as core sampling tool. A great student idea was to take the sample and then instead of trying to take the sample out (frustrating and often crumbles) simply cut the straw at the sample.
  • Work on labeling of cupcakes. What is the north side of the cupcake?
  • More scaffolding is needed turning evidence into a graphic.

Writing like a Scientist

The wheels on the Yeast is a living organism bus are almost wearing off. My 7th graders have performed an experiment, observed a demonstration, designed an investigation and worked with microscopes to collect evidence to support the claim about yeast. Beginning with characteristics of life, we’ve followed the pattern of experimentation for a class balanced with processing of information for a class. It’s been an engaging time and I’ve been impressed with the improvement in many students – and the year has just begun!

So far, feedback has revolved around classroom conversations. (Yep, I will work on collecting more responses from individual students as the year progresses.) To wrap up this series, I want my students to write up their evidence to support the claim. My thinking is to not focus on the structure of a traditional scientific lab report but to spend time on the processing of information and how students write up their ideas.

This year, I am super fortunate to work with a resourceful ESOL teacher who is helping me be more deliberate in the teaching of science writing. So helpful that he came in and worked with students in a mini-lesson. How do we write as a scientist?

Using the following excerpt from their text book, the students were asked to begin noticing features of scientific writing. Slowly, the page became more and more annotated as students provided examples of verb tense, linking phrases, active vs passive voice. The term “modal verb” was a new one for them but the idea of structure to explain things not fully certain was understood.

Screen Shot 2014-09-05 at 11.43.46 AM

They brought up the need for expanding vocabulary and using specific words. After the short mini-lesson, students began compiling all of their evidence and thoughts from the various activities into one place. They’re working on drafts to support the claim that Yeast is a living organism.

The need to be deliberate and explicit in my teaching becomes more and more apparent as the years go by. If the goal is for students to write a strong report, then they need to be provided with the support and scaffolding to improve their writing. We’ll come back to these skills throughout the year as I hope my students begin writing more like a scientist. I’m curious – what are other folks doing to help build writing skills in science?