Using formative assessment for individualized instruction

As part of the unit on Natural Selection and Evolution, I use antibiotic-resistant bacteria as an example of evolution that we have been able to see and measure in real time. At this point in the year, we haven’t talked much about bacteria, so my students don’t have a lot of background knowledge about them. The past couple of years, my bio colleagues and I have used the Antibiotic Sensitivity lab to give students a hands-on experience of working with bacteria, agar plates, and antibiotic disks. (If you haven’t done this lab before, both Flinn Scientific and Carolina have kits that give you everything you need.)

Students read the results of their lab about 24 hours after they plate the bacteria. They have to look for and measure any zone of inhibition around the antibiotic disks that they placed on the agar. From this, they have to conclude whether the antibiotic is effective against the bacteria.

Students measure the diameter of the zone of inhibition

I did not have students prepare a formal lab report for this assignment. Instead, there were a few targeted questions asking about how they know if the bacteria is resistant to an antibiotic, and how they would determine which antibiotic is most effective against the bacteria. I was looking for evidence that students understood that if an antibiotic is effective against bacteria, there will be a clear zone of inhibition around the disk where the bacteria were killed. If the bacteria was resistant to the antibiotic, then there would be no zone of inhibition around the disk.

Within the first few assignments I started grading, I quickly saw that students were reversing the two results. It was one of those “ooooh dear” moments, so I started spot-checking answers across all of my classes to see if it was a fluke (I was crossing my fingers!), or if there was a real pattern emerging. Sure enough, a significant number of students thought that if there was a zone of inhibition, that meant the bacteria were “resisting” that antibiotic.

Ooooooops. Double oops, when I considered the fact that there were questions on the upcoming test that assessed this concept. But I was also running out of time – there was only one class period before the test. At first I thought that I would reteach the concept to the whole class, although that would take away time that I had planned to give them for review. Thankfully, the lightbulb went on and I realized I could do a quick spot check to figure out which students did not understand. Then I could pull them aside for some one-on-one review.

I teach at a 1:1 school, so I knew I could use a Google form for quick answers. I started with a photo of a bacterial plate with five antibiotic disks on it, showing a range of zones of inhibition. I edited the photo to number each disk. I wrote four brief questions: (1) which antibiotic is the bacteria resistant to (they could choose as many as they wanted); (2) if the bacteria are resistant to an antibiotic, what will you see on the petri dish (short answer); (3) which antibiotic is the most effective against the bacteria (multiple choice – they could only choose one); and (4) explain how you know which antibiotic is most effective against the bacteria (short answer).

I had students fill out the Google form at the very beginning of class. After everybody had submitted their responses, I could quickly see who understood and who did not.

I also exported the data to a Google sheet so I could identify which students answered incorrectly. (I set the form to automatically collect their email address.) For those students, I had a paper copy of the image I used. I went to each student individually and went over the answers to make sure they had the correct information. They got an annotated copy of the correct answers to put in their notebooks so they can refer to it when they are studying for their test.

The best things about this were that I could find out exactly who needed help, and that it only took a few minutes of class time to find out the information!

Before-During-After Drawings – Helping students differentiate between diffusion, osmosis, and active transport

Students seem to have difficulty sorting through the different types of cell transport, because it’s such an abstract concept. Even after reading the textbook, taking notes, and doing different activities, my students didn’t understand the difference between diffusion, osmosis, and active transport. I created a handout for my students to use as part of our review for the test that had them visually explain what was happening during each process.

The basic format is one of the formative assessments Paige Keeley sets out in her book, Science Formative Assessment (volume 2). She calls them “B-D-A Drawings”. Rather than do each process separately, I created one document to compare the three processes. It was a spur-of-the-moment creation, so I hand-drew the drawings for the “before” panels. One benefit of giving students the “before” drawings is that they’re all using the same basic shapes for solute and water, and the same number of molecules, and I can set it up to guide them toward what their “during” and “after” drawings will contain.

Students got this basic template, with the “before” drawings

I did a jigsaw activity for this handout – I counted off students as 1, 2, or 3, then put each number at a separate table. Each table was assigned one drawing to complete. As each table worked on their drawings, I circulated through the room to answer questions they had, or to ask groups questions to prompt them to think about what would happen for their assigned process. When the group working on diffusion seemed stuck, I did a quick demo with a beaker of water and some food coloring. The osmosis group had the right idea about water moving (instead of solutes), but when I saw that their drawings did not change the water level, I asked them what would happen to the water level on each side.

Students used their science notebooks to help them think through their processes. It took them about 5-10 minutes to discuss what they thought would happen and draw the “during” and “after” diagrams. It also prompted a good discussion about equilibrium – how it would be different for each process, and how the active transport process wouldn’t reach equilibrium.

After each group had completed their set of diagrams, I regrouped students so there was one person with each diagram at a table group. Each student had to explain their diagrams to their tablemates and answer any questions. After each student had explained their process, students had to complete the diagrams for the two processes they didn’t have.

My answer key – oops, forgot to take pictures of student samples!

Overall, this activity gave students a visual explanation of the differences between diffusion, osmosis, and active transport. With larger classes, you could create multiple groups for each process to keep group size small enough to keep students focused on the work.

Quick Takes: Reviewing with Tarsia puzzles

If you haven’t heard of Tarsia puzzles, they are kind of like jigsaw puzzles and kind of like a matching game. They remind me a lot of Triominoes – that game with triangular pieces with numbers on each side, and you have to match numbers to create a big triangle.

Tarsia is the brainchild of Hermitech Laboratory, and is software that will create customized card sort activities. I think it was originally created for math teachers, but it can easily be adapted (with some workarounds) for any content area. (One caveat: there is no Mac option for the program – I’m lucky to have access to both Mac and Windows computers, so if I want to make a Tarsia, I make it on my home computer and save it as a PDF to print at work.)

The Tarsia software has a variety of geometric shapes to use – triangles, hexagons, rectangles, etc. – and make a puzzle with between 17 and 30 paired expressions. There’s a standard version, where the outside edges are left blank so students can easily find the borders, and an extended version, where there are unpaired phrases on the outside edges so it’s more challenging to figure out the borders.

To make a Tarsia puzzle, you create a list of paired words or expressions. (The software also allows you to insert images, but I haven’t tried that yet.) The major limitation for the paired words is space – since the software was originally created for math, there’s only room for a few characters. Once you get more than about 20 characters, the print size and spacing between words gets so small it’s difficult to read. Not as much of a problem if you are creating tabletop-sized pieces for students to use. However, if you want to use them for student notebook activities, you’re reducing the size of the puzzle by a decent amount, making it very hard for students to read the text. I’ve used a blank template and handwritten the paired phrases if I’m worried about legibility (or if I’m at work and want to make the puzzle).

Handwritten phrases in a blank template

Once you created your paired phrases, the software creates pages with scrambled puzzle pieces. There are usually 2 or 3 pages of shapes, so what I do is print them out and reduce the size of the images until I can fit all of the pieces onto one sheet of copy paper.

A one-page Tarsia handout for student notebooks. (See what I mean about legibility?)

When I give students this one-page handout, they cut apart the pieces and then have to create the completed puzzle, matching words and phrases. A word of caution: it takes students a loooooong time to complete the puzzle. I usually have them work in pairs, with the understanding that each student needs to have a completed puzzle in their notebook. I have a completed puzzle in my notebook to use as an answer key, so I can easily check student work. I also have a photo of a completed puzzle that I can project on the board so everyone can check their own puzzle.

The answer key – a completed puzzle!

This activity is great for reviewing vocabulary and basic factual information. Obviously with the size limitation, it isn’t great for more in-depth information. I plan to experiment with using images in a puzzle – I think that would be great for a beginning-of-the-year practice for lab tools, especially the different kinds of glassware.

Quick Takes: Fill-in-the-blank review races

I love a good Kahoot as much as the next teacher, but they do have their limitations. Sometimes I want a review activity that has a little more conceptual heft. And sometimes I need to mix things up so it’s not “all Kahoots all day”. I’ve used cloze reading activities in the past, so it was an easy pivot to make them into a review activity.

A good starting place to make a cloze reading activity is the supplemental materials that are commonly published with textbooks.* The book we use, Biology by Miller and Levine, includes summaries of each textbook section. I adapt those by using the parts of the section we covered, and then add information from other activities (including labs or class notes). Once you have the basic text, you strategically replace words or phrases with blanks. Many times, I will remove a vocabulary word but also add some context clues so students have to understand the meaning of the vocabulary word to correctly fill in the blank.

You can use a cloze reading activity at any point in an instructional unit, but I like to save them for review days. By that time, we’ve covered the content through reading, note-taking, labs, and formative assessments. Using the cloze reading is a form of retrieval practice. As I tell my students, “The information is in your brain already, you just have to teach your brain how to find it.”

And of course, kids love review games. I pair students, usually with their table partner, and have them set their notebooks on the table for easy access. I set this review up as a race – partners work together to fill in the blanks, and the first group to correctly complete the reading gets a prize. (I usually give prizes to second place winners as well.) By working with a partner, students who are less confident in their knowledge still have a good shot at winning.

I hand out the reading by placing it face-down in front of each group, telling students to leave the paper face down until I get all of them handed out. And then it’s “Ready . . . Set . . . GO!” While they’re furiously working, I am at my desk with the answer key. As a group finishes, they come up and I mark any blanks that are incorrect and send them back to keep working. If multiple groups are finished, they form a line at my desk so I can check their papers in order.

Once winners are declared, I project the answer key – all students are expected to complete a reading worksheet and glue it in their notebook. I also ask students to reflect on how well they knew the answers and use that reflection to plan their study time. I can also take questions to clarify any knowledge gaps or misunderstandings.

In my experience with this review activity, all students are engaged to the very end. And it only takes ten minutes, so I can do other review activities during the same class period. I also send a blank copy (and the answer key) to our Center for Student Success so the teachers there can use it to review with students who have a CSS period (supported study hall).

*I can’t include a sample, since the worksheets I make are derived in large part from copyrighted textbook materials.

Quick take: Commit and Toss Formative Assessment Technique

One of my goals for this school year is to increase the amount of formative assessment as a way to check for my students’ understanding. When I saw a package deal at NSTA for Page Keeley’s Science Formative Assessment books, I pounced! Such a deal for 125 formative assessment techniques. I am slowly working my way through the books and figuring out how to incorporate more of them into my instruction.

Page Keeley’s Science Formative Assessment 2-book set – highly recommend!

The first one I used was “Commit and Toss”. During the previous class, we had looked at The Biology Corner’s The Lesson of the Kaibab, a case study looking at the impact of population size on ecosystem resources. Part of the case study addressed how removing the deer’s predators caused the deer population to skyrocket, leading to depletion of the deer’s food sources. Students made a graph tracking the population size of the Kaibab deer herd before the predator removal, after the removal, and later, after the predators were reintroduced. For this formative assessment, I used the prompt “Was the Forest Service’s plan [to remove predators] successful?” and asked students to commit to an answer and justify it.

The key part of Commit and Toss is that students do not write their names on their response. This reduces any stress to have the “right” answer, or to be embarrassed about sharing their answer to the whole class. I gave my students a few minutes to write out a response, then gathered them in a circle. I gave the instruction, “Okay, now crumple your paper into a ball”, then had them turn around so their backs faced the inside of the circle, and drop their crumpled paper into the center. (The book says have students toss their papers, but I have some rambunctious ninth graders and I could easily imagine what THAT would look like!) To mix things up a little more, I had students collect a paper ball from the center, and then we repeated the over-the-shoulder drop again.

After the second round, students opened their paper and silently read their response. I then sorted the responses into 3 groups: Yes the program was successful; No the program was not successful; and The program was kinda successful. Each group took a minute to review the responses and choose one or two responses that they felt had the best justification for the answer. Then I had each group share those responses to the whole class. When the group shared, I had them start with “The papers we got said . . . ” to disconnect the student from the answer so they didn’t have any attachment to whether the answer was right or not.

Overall, I loved the Commit and Toss technique. It was a quick way to check in with how students processed the information in the case study and how well they understood the cause-and-effect link between the removal of predators and the deer population size. The other thing I appreciated was that my students got to hear their classmates’ reasoning for whether the Forest Service program was successful or not. Immediately following the Commit and Toss exercise, I had students write a brief reflection in their notebooks about what they learned from this case study.