Claim, Evidence and Reasoning (C.E.R.)

Answering Free Response Questions

  Assessing student learning is as important as it is difficult. To truly teach well, we must understand what our students do and do not understand so that we may facilitate their learning as we move forward. There are many, many different types of assessment each with their own merits. If, however, I really want to get a strong feel for how my students are understanding a topic, I am going to have them write about it. This writing could be a quick write during class, a ticket out the door at the end of class or an assignment that requires free response answers. As a science teacher, however, I struggled with helping students to construct strong free response answers. They may have a sense of the material, but really had difficulty in articulating their understanding. In my many years of teaching, I never had a good solution to help my students to write clear, detailed, yet concise science answers. I would model how I would answer the question myself and this would help a bit, but most students still struggled. On a particularly frustrating day, I brought up this topic with a colleague of mine and she suggested that we ask our local science consultant. It was at this time that I was introduced to C.E.R. = Claim, Evidence and Reasoning.
  CER has really transformed both my formative and summative assessments. I now teach my students this framing for their free response answers and receive on a whole a much better written set of answers on any free response question given. Having the frame helps students to know what components should go into an answer, where they should go in the answer and how those parts should be related.
  When teaching students how to use CER for their answers, I first give them these simple instructions:
1. Claim = your answer. It is probably all that you would put in that blank space after the question unless I forced you to give me a more detailed answer.

2. Evidence = the information that supports your claim. It may be from a lab or from some content that you learned in or out of class, but it backs up your claim.

3. Reasoning = The statement or paragraph that explains how your evidence supports your claim. It is the part of the answer that ties everything together and summarizes the information you are giving in response to the question.

CER can be taught to relatively young science students as early as the middle elementary grades. At the start, have students fill in the parts to the frame. "What is the claim?" What is the evidence?" and What is the reasoning?"As students grow older and have more practice at it, their answers should become more detailed and more fluid. Eventually students should eliminate using the frame as they just write a comprehensive paragraph or paragraphs answer.

  Below are two examples that I would share with students in a middle school physical science class.

EXAMPLE 1 – HOW TO USE C.E.R. FROM A LAB

Lab Question– How does the height of the ramp affect the speed of the car?

Height	Speed
100cm	200cm/sec
60 cm	150 cm/sec
30 cm	110 cm/sec

Question - How does the height of the ramp affect the speed of the car?

Claim – The higher the ramp, the faster the car travels.

Evidence – As the height was increased from 30cm to 100 cm, the speed increased from 110cm/sec to 200 cm/sec.

Reasoning – Therefore as you increase the slope of a ramp you cause the car going down the ramp to go faster as evidenced in our lab. The higher angle of the ramp gives the car more potential energy. This potential energy is then converted into more kinetic (motion) energy as it goes down the ramp.

EXAMPLE 2 - HOW TO USE C.E.R. FROM A LESSON

Lesson  - Acceleration can mean many things in physics. It can mean speeding up, slowing down and even changing direction. The definition of acceleration is the rate of change of velocity.

Question. Two kids are arguing about physics. Richie says that the Earth orbits the sun at a constant speed and is not accelerating, but Litisha says that the Earth accelerates as it orbits the sun. Which physics student is correct?

Claim – Litisha is correct. The Earth accelerates as it orbits the sun

Evidence –Acceleration is any change in velocity.  Velocity is speed AND direction. If the direction changes then the velocity is changing and any change in velocity is acceleration.

Reasoning –Since the Earth is constantly changing direction as it orbits the sun, it has a change in velocity and any change in velocity is acceleration.

CER may appear to be a small addition to your teaching tool belt, but I have found it to make a daily difference in both how my students write and how I am able to assess their understanding. As we move into the age of the Next Generation Science Standards and the Common Core we see the recurring theme of evidenced-based reasoning. The use of CER is an outstanding to aid students in their learning to engage in evidenced-based reasoning!

White Boards

I love to use technology in my classroom and at home. I have multiple tablets, Apple TV, Tivo's, a smart projector and my smart phone hard at work on a daily basis and I plan to write about how I use that technology in a future blog post. Today, however, I am going to focus on the low tech, but high impact use of white boards. Whether you are in the classroom or home schooling, white boards have a myriad of creative uses that instantly increase engagement for your students.

White Board Purchases
I have three different size white boards sets in my classroom. The largest, as seen in the picture above, are 23" x 31". These are available from White Boards USA http://www.whiteboardsusa.com/ and are fantastic in group work activities. I have a second set of slightly smaller group boards that I had cut from shower board at Lowe's. I had one $10 board cut into 8 equal sections. They are not the same finished product as the ones purchased as white boards, but they still work well. Lastly, I used the same shower board from Lowe's to make individual white boards for each student. They are about 14" x 11". I have one under every desk in a 2 gallon zip-top bag with a black dry erase marker and a piece of felt to use as an eraser. The markers are a bit of an expense, but this year I added dry erase marker as an optional school supply that my students needed for class and I have been pleasantly surprised by how many brought in their own and how they love to use their colored markers to express themselves!
 The uses for white boards are truly endless. They are well used at the beginning of a unit to elicit students preconceptions about a topic, used during a unit to practice concepts or problems and are always used at the end of my units in a white board review.

Why White Boards?
1. Students love them! They ask to use them constantly and are always excited when I tell them to grab their white board and ______________.

2. There is a sense that answers on a white board are not permanent and therefore less threatening as opposed to putting an answer on a sheet of paper.

3. Students can share their thinking with others. The vast majority of times that I use white boards in my class it is in activities where the expectation is that students will be sharing with other students. This helps to build the classroom community and encourages constructive discourse within the classroom.

White Board Ideas
1. Groups of students can design scientific investigations on a large white board. They can suggest ideas and modify them as the development of the experiment progresses.

2. Students can share predictions of what they believe will occur in a lab or activity.

3. Students can share their understanding of why something occurred. As they explain themselves (developing those communication skills!) they can use the white board to help illustrate their thoughts and help others to understand their thinking.

4. Students can diagram their thinking. Often times it is easier for students to sketch out their thoughts, use arrows to show connections and then write or verbally explain their thinking. Again, the white board is a perfect format for this type of activity because it allows for easy modifications of thought.

5. White board reviews. For almost every unit that I teach, I write a white board review series of questions on Power Point. I flash the questions, one at a time on the screen and then students write their answers on their white boards and hold them up for me to read. I get instant feedback on what they know and what they do not know. It is true that these questions are written so that the answers only require a single word or a short phrase, so I don't get in depth feedback about their true understanding. I do, however, get a feel for where the class is at on each topic and can then ask verbal questions to probe their understanding.

6. Students very often come into my classroom before school, at lunch or after school to get extra help. When working one-on-one or in small groups we often pull out the white board and make our thinking visible to help all understand the concept better.

7. Play Pictionary with the white boards. Place the class into teams and give the drawer for each team a term or concept that they must draw out while their team mates try to guess the answer.

One supposed disadvantage of the white board is that it will be erased and unlike a sheet of paper, you can't  take it home and study it. Or can't you? That is where the technology jumps in. Students very often use their cell phones to take pictures of their white boards so there is a permanent record of their thinking. I have also often taken pictures of white boards to share with classes. At times I have used them as a timeline of the progression of thought as we have moved through a unit. I have also posted pictures of two white boards next to each other allowing students the opportunities to compare the thinking displayed on each.

Planting Peanuts

YUM! Peanut butter. PB and J sandwiches. Peanut butter cookies. Peanut butter is great in so many ways, but where does it come from? You probably know that it comes from ground up peanuts, but where do the peanuts come from? Peanuts are the seeds of peanut plants. A peanut plant produces flowers just like many plants around your house. Once the plant flowers, pollination occurs allowing the pollen from one part of the flower to come together with ova (like little eggs) from another part of the flower. They join together to form the seeds - or peanuts - of the plant. A peanut plant is rather unusual because after flowering, the stems where the seeds are beginning to grow bend down towards the ground and the peanuts actually develop underground. Check out a picture here: http://www.bhg.com/gardening/plant-dictionary/vegetable/peanut/ The peanuts are ready to harvest after about 3 months. These peanuts would not be tasty because they have not been roasted. The peanuts that we eat at baseball games and that are used in making peanut butter have been roasted bringing out their peanutty flavor and eliminating the "green" flavor of a raw peanut..

  You can grow your own peanut plant at home. Fill a plastic cup or pot with soil. Place the raw peanut, the shell and the nuts inside, about 2 inches beneath the top of the soil and cover the peanut with soil. Moisten the soil with 4 tablespoons of water. Keep the peanut planter in a warm area and remember to keep the soil moist. A peanut plant will emerge within a week and it can flower within few months.

-Growing a peanut plant is a great activity for homeschooling or the classroom. Many kids have planted seeds from a seed packet, but few have ever planted a seed bought from the produce department of their grocery store.

- Students can learn about seed anatomy as they study the peanuts before planting. A peanut plant is a dicotyledon.It has two parts in its seed as compared to a monocot, such as corn, that one has one part.

When a student separates the halves of a peanut, they will notice the small embryo tucked at one end and if they look very closely, they can even see to leaf-like sprouts popping out of it.

The majority of the peanut is actually food for the growing peanut plant and this is why it is also a good food source for containing  many unsaturated fats and proteins. If teacher or parent supervision is available, you can actually put a peanut on a pin and light it with a match just as you would light a candle. This is a clear indication of how much oil is in a single peanut.

-Like any seed planting activity, students can design different experiments to test the germination of peanut seeds. Here are a few suggestions:

  1. Try soaked in water peanuts versus non-soaked peanuts.

  2. Try peanuts in the shell versus peanuts not in the shell.

  3. Try different soil types for growing peanuts - clay, sand or potting soil.

Quotes in Teaching

"A teacher affects eternity; he can never tell where his influence stops."
                                                                     --Henry Brooks Adams
Just like teaching itself, quotes can have a great and lasting influence on students. There is a multitude of ways that teachers can use quotes in their classroom including to send a message in words other than our own and to inspire students to seek out their x-factor and individuality.

Using Quotes in the Classroom
1. If you do a bell ringer or calendar question each day in class, occasionally pick out an inspirational quote and ask students to interpret the quote and share their interpretation either in a think-pair-share format or with the class. This is also a great opportunity to expose students to a wide variety of people with which they may not be familiar. For example, a quote by Neil deGrasse Tyson allows you to share not only his wise words, but also some information about him and what he has meant to the science community.

2. Use quotes when asking the students to do some goal setting. Two of my favorites are:
  “Whether you think you can, or you think you can't--you're right.”
                                                            --Henry Ford
  "A goal is a dream with a deadline"
                            --Napoleon Hill


3. As an opener to the school year, have each student do a web search and find a quote that is meaningful to them. They can share with the class why they chose that quote and what they learned about the person who made the statement. If students keep a class folder they could even add their inspirational quote to their front cover of the folder.

4. Have students write their own quote. What are the words that they live by? Again, students can share these in class or write them on their folder covers. If available, you could also put all of the quotes on to a class bulletin board.

Here are a few more of my favorite teaching quotes:
"The ripest peach is highest on the tree."
                           --anonymous

  “No one can make you feel inferior without your consent.”
                                            --Eleanor Roosevelt
  

Science is built up of facts, as a house is built of stones; but an accumulation of facts is no more a science than a heap of stones is a house.”

                                            --Henri Poincare

Slime Molds

The picture you see above is that is a humble slime mold growing in some wood chips beneath the toes of unsuspecting school children playing at a playground. As a science teaching tool, the slime mold is unparalleled in engaging students asking questions, designing experiments and learning how to engage in evidenced-based reasoning and argumentation.

Objectives:
1. Science as discovery. Students will learn to make keen observations, ask questions and build evidenced-based arguments to support their thinking.

2. Discovery - Students learn about a species they may have never heard about and find that it is both simple and complex depending on how you classify it and to what you compare it.

3. Classification - students learn that slime molds are very difficult to classify having qualities that are fungus-like, animal-like, plant-like and protist0list.

Preparation:
1. Order slime mold in the dormant stage from Carolina Biological Supply Company. Here is a link to the specific product.
http://www.carolina.com/slime-molds/physarum-polycephalum-sclerotium-living-box/156190.pr?question=

2. Prepare or order petri dishes filled with NON-NUTRIENT agar. The agar must be non-nutrient to keep down bacteria and mold growth on the agar.

Procedure:
I chose to do a slime mold activity literally the first day of school in the fall. Students come in, we do the typical meet and greet and then students get to work.

1.after placing the students in pairs, I describe a situation of having an unknown substance that we want to learn more about. Each pair receives a small piece of paper with a yellow, dried substance on it. They are instructed not to touch it in order to not contaminate it or themselves.

2. Students draw pictures and write descriptions of their "unknown substance".

3. I demonstrate sterile technique and then students use sterile technique to place the unknown substance on the top of the agar (using forceps), replacing the lid on the petri dish and writing their initials on the side of the dish. (I do not explain the function of the agar until the entire activity is over).

4. Store the dishes in a cool, dark drawer.

5. On the second day of class, students will examine their dishes and find that the unknown substance has spread out on top of the agar. After students have again drawn pictures of their substance and written descriptions of what they see and how it has changed since yesterday, I ask the question "Is the substance alive". I have students discuss this question with their partner and with other students in the class.

6. After their discussions, I have students use sterile technique to add a small piece of oat flake (again - I do not identify this substance) to the top of the agar in their dish.

7. Again, store the dishes in a cool, dark drawer.

8. On the third day of class, students will see that their yellow unknown substance has moved and is now on top of the second item (oat flake) added to the dish.

9. After students make their sketches and write their descriptions, ask again "Is the yellow substance alive?" As a class, have students provide their evidence to support their argument. There is much evidence that the slime mold is alive and students can refer to its stimulation by the wet agar, its movement, the transition to the food source and its growth. Depending on time, teachers can move forward in several possible ways:

  A. Reveal that the slime mold is indeed alive. You can share the information from Carolina   
     Biological Supply or you could should the video clip or article with links given below.

            1.  Video – PBS. org

            http://video.pbs.org/video/2300863877/

            2. Slime Mold Article – Smithsonian Magazine

            http://www.smithsonianmag.com/science-nature/phenom_mar01.html
  B. Have students design and carry out simple experiments to test life characteristics of the slime
     mold. The living mold can easily be cut, moving a piece of it on its agar to a new agar coated dish.
  C. Students can design mazes for their slime molds. They can either cut the agar into different maze
     shapes or add different features such as bridges or moats to their agar dish.

10. Lastly, spend a little time on the classification of the slime mold. Explain why they are difficult to
    classify and how they are currently classified.
  Here is a link to a discussion of their classification:
   http://www.princeton.edu/~achaney/tmve/wiki100k/docs/Slime_mold.html
 

Cartesian Diver

Make a Cartesian Diver
  This a simple experiment that applies several interesting science concepts. It is suitable for children 6 and older but should me made with adult supervision.
Materials:

•   Fast food or Chinese food condiment packet

•   Empty plastic soda or juice bottle.

Procedure:

1. Clean and empty the soda or juice bottle.
2. Gently push the sealed condiment package into the empty bottle.
3. Fill the bottle almost to the very top with tap water.
4. Squeeze the bottle and watch the "diver" dive as you apply pressure. If the diver does not dive you can trouble shoot with the amount of water added to the bottle. It may take a bit more water than what you started with, or a bit less, but the water level should always be close to the top.  

The Science:
  The Cartesian diver is said to be named after the great explorer Rene Descartes who may have been the inventor of the toy. With no pressure on the bottle, the condiment package is buoyant meaning that there exists and upwards force from the water on the package keeping it afloat. The diver is not very dense meaning it has little mass per volume. When the bottle is squeezed, only the air in the bottle can be compressed (liquids cannot be compressed). The only air in the bottle is at the very top between the top of the water and the bottle's cap and a small amount of air in the condiment package. That small amount of air in the packet is the key! When the air in the condiment package is compressed, the package becomes less buoyant because it has the same mass but takes up less space (it is more dense). With less buoyancy the package can sink to the bottom of the bottle.

Extensions:Young scientists can . . .

1. explore with different types of condiment packages.
2. color the water (with adult supervision) or use water-proof markers to color the condiment package.
3.  maker a diver game by  bending a small piece of wire into a hook shape and taping it to the condiment package. Next, take another small piece of wire and shape it into to any shape you like, but include a loop of wire on the top. This "treasure" you have made must not be buoyant, but also must be light enough that it can be picked up by the hook on the condiment package. Now  the young scientist can squeeze the bottle lowering the hook and try to retrieve the sunken "treasure".
4. experiment with soda water filling the bottle.