Wednesday, April 12, 2017

15 Graphic Organizers For Text Structure Work

This week I participated in some great professional development about text structures, led by my colleague, MaryAnn Tatarunas. She explained that student understanding of text will improve when they are directly taught five text structures. Each of the five text structures can be identified by key phrases that are included in the text and they can be better understood by considering certain key questions. 

Here is a quick rundown of the five text structures:
  1. Causation: cause and effect relationships are explored, phrases like "as a result as" and "because of" are often used
  2. Comparison: things are compared or contrasted, phrases like "alike" and "different" and "as opposed to" are often used
  3. Description: information about a topic is presented, words like "characteristics" or "properties" or "qualities" are often used
  4. Problem/Solution: a problem and solution are explored, words like "answer" or "response" or "puzzle" are often used
  5. Sequence: an order of events is presented, words like "before" and "after" and "finally" are often used.
MaryAnn shared sample reading assignments with us for each of the text structures and then showed examples of graphic organizers that could be used with students to help them better understand the text and recognize these text structures.


I was so inspired by the practical tips that MaryAnn shared with us that I created fifteen Google drawing templates of some of these graphic organizers. They are color-coded by text structure. You can access them here. To use them, go to the file menu and select "make a copy" to make your own editable copy of the organizer. Google drawings are under-utilized but I really like them. They can be distributed through Google classroom or with Doctopus so that each student gets his/her own copy for individual work. Also, teachers can add text blocks in the gray space on either side of the drawing canvas to create drag-and-drop experiences because the stuff in the gray space gets shared right along with the drawing on the canvas. 

It's standardized testing season in Ohio. We just wrapped up testing at my school, but at this time of year, we are all reminded about the importance of helping students use all available strategies to be successful on these tests. Certainly teaching students to recognize text structures and apply appropriate graphic organizers will improve reading comprehension, a handy skill to have at test time.

Feel free to copy and share these graphic organizers. I will be adding more to the collection in the coming months.

Wednesday, April 5, 2017

Using Stop Motion Animation to show Reaction Mechanisms

Kinetics is a topic that I love to teach, but my students find it very difficult to understand. There are probably a variety of reasons for this, but one that I think contributes is that students struggle to think at the particle level in chemistry. If it's difficult to think about a sample of matter as being made of indescribably small and invisible particles, it is probably even more difficult to consider or propose the order of collisions that must occur in a successful chemical reaction. That is one of the challenges of teaching reaction mechanisms.

When the reaction     2 NO2 + F2 --> 2 NO2F    takes place, we know the reactants are 2 NO2 and F2. We know the products are 2 NO2F. We don't know, from the balanced equation, which particles must smash into which particles in order to change the reactants into products. We do know, though, that it is statistically unlikely that all three particles must crash into each other at once and instantly form products. Scientists propose a mechanism that outlines the order of the collisions that gets us from reactants to products.

I use a guided inquiry activity to tackle this topic every year. During my small group discussion with kids, I often need to use something to model the collisions that happen between the reactant molecules in the example reactions. Sometimes I use paper circles and sometimes circles I have drawn on the iPad. This year I grabbed small colored plastic cubes because they were handy. As I was talking with a student about the order of molecular collisions, it occurred to me that this would be a great occasion for a stop motion video, especially because, as a GIF, it could be watched over and over again until a student really understood the differences in the order of collisions of the same particles in two different mechanisms. 

I grabbed my iPad and took four quick pictures as the student and I talked through these collisions. Using the Stop Motion app, I created the GIF in fewer than five more minutes. Here it is:



It was very easy and can now be used as a tool to help students see the difference between two mechanisms. Next year I will try to incorporate making stop motion videos into the guided inquiry.

Tuesday, April 4, 2017

Modeling Reaction Kinetics

In my last post, I detailed my takeaways from a powerful workshop I attended on modeling instruction. Since attending that workshop, I find myself thinking more about incorporating the ideals of modeling into my instruction. For years I have created open-ended activities in which students explore and test hypotheses, but questions have remained. How can I make better use of my whiteboards? How can I facilitate more conversations about student experiments?

One of the first topics I applied some of these modeling ideas to was kinetics. Kinetics is one of my favorite topics to teach, so it was a perfect starting point for this new inspiration. For years I have attempted a clock reaction lab in hopes that students could use data to write a rate law. Unfortunately, the results are usually a mix of inconsistent and confusing and rarely lead to even a better understanding of rate laws in general. I have led students through at least four iterations of rate law labs, each year junking that year's plan and vowing to do it better in the future.

Here is what I tried this year: On Day 1 of the Kinetics unit, I demonstrated a clock reaction for my students by mixing a solution of potassium iodate and a solution of sodium hydrogen sulfite. It's a great hook. Then I posed the question "does the concentration of both reactants affect the reaction rate to the same degree?" I sent students into the lab with 10 mL of each reactant and some tips. I asked them to collect at least 10 data points that would support the position they took to answer the question. They completed the experiments in a spot plate, measuring the solutions by drops. Most groups took between 20 and 30 minutes to complete their data collection.




I had ordered whiteboards from The Markerboard People. Each group took a whiteboard and created a graph that showed the concentration of each reactant vs time. Without revealing the whiteboards, I asked each group to summarize their experiments. Most groups conducted similar experiments, so I asked the students to hypothesize whether or not they guessed the data, and the relationship between concentration and rate, should also be similar from group to group. They said yes. Then they revealed their boards. And the data was not the same.

I asked students to talk about their data. What did it tell them? How did they explain why their graphs looked differently? What did they notice about each other's representation of information. The conversation was fantastic. Students used math vocabulary ("It looks exponential" and "This section looks linear but we might have an error that explains that" and "why would you make the scale on the x-axis run backward?") to describe their graphs and identified, without my prompting, errors that might have contributed to poor data.

In the end, they wouldn't have been able to determine a rate law, but I'm not sure that is even what's important here. I kept coming back to the essential question: Do the reactants affect the reaction rate to the same degree? Students seemed almost unanimous that the reactants have different effects on reactant rate. That notion laid exactly the right foundation for the next day's learning about rate laws.