Over the past two weeks, I have been working on teaching my Understanding by Design unit on gases and gas laws. I started teaching this unit on Thursday April 7th, and completed the unit on Friday April 22nd.

**Day 1: **This unit started with a pre-test, given on the 7th of April. This was given immediately following the conclusion of the previous unit. After students finished the pre-test, I asked students to pick a partner they were comfortable working with, and they were instructed to brainstorm about the relationships between three pairs of gas variables: volume and pressure, pressure and temperature, and volume and temperature. I wanted them to think together about how a change in one affects the other, and then see if they could come up with any real world examples. Here is a copy of the worksheet I gave all students: Introduction to Gases.

After students had enough time to discuss with their partners, different groups shared their responses with the rest of the class and we discussed what they had come up with. This prompted an introductory discussion on what is meant by gas pressure, which helped with students confusion pressure and volume. In the future, I will be starting this unit (after the pre-test) by discussing pressure in more detail with all classes before the brainstorm. After the first few classes, I discussed what gas pressure was very briefly, which seemed to reduce the confusion experienced by the first few classes.

After the group discussion about the relationships between the pairs of variables, students were asked to pick one of the three pairs to test via lab in the next class period. I encouraged students to pick the relationship they understood the least out of the three we had just discussed. Students were given a copy of the lab they picked to look over before the next class period so they would be familiar with the procedure before they started. Of the three possible labs, two used Vernier Lab Quest 2 equipment, and one used traditional lab equipment.

**Day 2&3: **During the first class period, I observed a very high level of engagement in the activities and students were excited to see the relationships in real world examples. After students had collected data, we got back together as a class during the next class period and I had students graph their data and based on the shape of their graphs, students identified their variable relationship as either direct or inverse.

**Day 4: **This was the first day of notes that were given by direct teacher instruction. I also performed two gas demonstrations for the students to show real-world examples of the gas laws in action. I asked students to think about which gas variables were involved in each demonstration, and then had a class discussion about what happened in each demonstration. Students were very engaged during the demonstrations and seemed to like the real-world examples of what we were learning about.

**Day 5: **I instructed students on how to create a gas laws foldable to summarize the gas laws we had covered so far. This will be their only resource for the post-test they will be able to use, besides a calculator. After the foldables were completed, I gave students a worksheet to practice gas law calculations. There were three levels of worksheets available, and I allowed students to select the level they felt most comfortable with. Here are the worksheets: gas laws worksheet 1 low level, gas laws worksheet 1 middle level, gas laws worksheet 1 high level. The only difference between the worksheets was the amount of assistance provided. The low level worksheet had the most support, while the high level had no support.

All students selected either the middle or high level worksheets. A few students that missed class that day were given the low level sheet to help them get caught up. These worksheets were completed during class time, but instead of students simply turning them in when they were finished, I checked every single worksheet as it was finished to provide all of my students with immediate feedback on their performance. If students needed more scaffolding, I was able to provide it at this point, and if students had a solid understanding, they had their worksheet checked off and they were done for the day. Depending on the class, anywhere between 5-20% of students did the high level worksheet, and the remainder did the middle level. While giving students feedback, it became clear that in the future I should go through examples of each type of gas law a few times before setting the whole class to work on their own. I made sure to go through examples with all of my classes at some point, however in the future I will start with examples for all of my classes.

**Day 6: **After most students had their worksheets checked off, we finished the last gas law of the notes. Before the end of this class period, students were given their first self-assessment of the unit. I used these results to get a feel for how students thought they were doing at this point in the unit. These results are included in the attachment that also includes the final self-assessment given at the conclusion of the unit. At this point, on a five-point scale, the average over all classes for student engagement, effort, and understanding were 4.07, 4.05, and 4.20, respectively. This showed be that no changes needed to be made so far, and we could move on to the next week without any adjustments.

**Day 7: **Today students were given one of three ideal gas law worksheets: Ideal Gas Law Practice low level, Ideal Gas Law Practice middle level, Ideal Gas Law Practice high level. These were different than the first worksheets because this time the high level worksheet had completely different problems than the other two. The high level worksheet had problems that added material from a previous unit, while the other two only focused on the ideal gas law. The middle level had the equation and variable definitions, while the low level had each question broken down into simpler steps. Again, no students chose the low level, but this time more students chose the higher level worksheet than for the previous worksheet. I provided feedback for this worksheet the same way I did the first, so each student got to see how they did right away. If corrections were needed, they went back to their seat to fix them, and if the problems were all correct, they were finished. This worksheet seemed to take students a few more tries to get the problems correct than before, and I think in the future to prevent this, I will spend more time going through problems with the whole class than I did this year.

**Day 8:** This was supposed to be a review day, but I was sick, so it turned into an extra work day for students to finish their Ideal Gas Law worksheets.

**Day 9: **I checked off any worksheets students had finished during the previous class period, and then we started reviewing. I gave students three real-world examples and had them get in groups to discuss, in terms of gas laws and general gas behavior, why each of them occurred. We discussed each together as a class, and then moved onto review using Poll Everywhere. Most students were able to participate in Poll Everywhere using their mobile devices, but those without simply wrote their answer choices on a piece of paper. Any time students did not pick the right answer, we had a quick discussion about why that answer was wrong, and what the correct answer was.

**Day 10:** This is the day of the post-test. A large number of students were gone for this because of sports and other reasons, so there will be a lot of student taking this next week as well. The scoring on the test is very straightforward. The first page consists of short answer questions, while the final two pages are calculation problems. After some consideration, I decided not to grade the first question because it was not a good question based on how the unit was taught. For question 2, students needed to mention the collisions of gas particles with the walls of the container. If a student did, they received credit, if they didn’t mention all of that, they either received partial credit (no mention of walls of container) or no credit (no mention of collisions). For question 3, students needed to list three gas pressure units discussed in the unit, and how to convert between them. If a student listed three units, but no conversions, they received 2 of 3 points. If they only included two units, they received 1 of 3 points. For question 4, students needed to state that the total pressure is equal to the sum of the partial pressures. That was worth one point. Students only received the point if they stated that in some way. If they didn’t mention the sum or were completely off, they received 0 points. Question 5 asked students to fill in the blanks for when real gases differ most from ideal gases. The correct responses were low temps and high pressures. This question was worth 1 point total, each blank worth 1/2 a point. These were either right or wrong.

Questions 6-15 were each worth 2 points. Students lost 1 point if they did not show their work for the problem. The answers were also graded on significant figures, or the correct number of digits in their answer. If a student had the wrong number of significant figures, they lost 1/2 a point. If a student showed their work and it was correct, but the answer was wrong (more than just sig figs wrong), they lost 1 point. If the work and answer were both correct, as well as sig figs, they received full credit.

After students finished the post-test, they were given a final self-assessment for the unit. The results from that and the first self-assessment can be found here: Student Self Assessments Gases Unit.

For effort, engagement, and understanding, all of my classes averaged together were 3.95, 3.88, and 3.83, respectively. This is a slight decrease over the first self-assessment, which I think in part is explained by my absence for one day during the final week. Students gave some comments about not having enough time on this survey, and I will be addressing this next week before we move on to the next unit. Based on the scores on the post-test, there are a few things that need to be addressed before I can feel comfortable moving on, so I will also talk with my classes about that next week.

**Individual Paths for Learning**

As students worked on and completed their two gas law worksheets, I checked them before they received credit to ensure that each student fully understood every question and got all of them correct. Some things that I noticed as I went through this process for the first worksheet was that some students needed extra help with the algebra aspect of the worksheet. One thing I will do in the future of teaching this unit is to make sure I review the algebra concepts with students that feel they need that help before I let them work on their own. I could also provide those students with additional practice problems until they feel more comfortable solving those problems on their own.

For the ideal gas law worksheets, there was some confusion with students on the units associated with one of the variables in the equation, so next year I will make sure to spend more time going over that as a class before students work on their own. This worksheet was similar to the first in that it is mainly algebraic in nature, and a majority of the issues I saw with the worksheet were math related, so I will make sure to spend more time with those students who may need that extra algebra support for next year.

**Effectiveness of Planning**

I originally planned for this unit to take about 14 days or so, accounting for block and short periods. The start of this unit ended up being pushed back a few days, so things were a little off from my initial plan. When I started planning this unit, I paid attention to how each lesson or activity fit with the differentiation strategies we discussed throughout the semester. The first thing that I thought about was ensuring students had a choice in what they were learning, which is how I came up with students choosing from one of three labs as an introduction to the gas laws. I wanted students to pick something that interested them, and would hopefully be engaging as they discovered one of the three gas laws we learned about in this unit.

When it came to the teacher-directed instruction, I focused on providing engaging demonstrations to keep students interested and hooked on the gases unit. The discussions that arose from the demonstrations I showed the students were some of the best I have ever encountered with these classes this year, and it really got students thinking about why gases behave the way they do. When I gave students the end of unit self-assessment, quite a few students wrote that their favorite part of the unit was seeing the marshmallow demonstration, which tells me that the demonstrations I did were an effective tool in this unit.

To plan for the different levels of students in each of my classes, I knew I had to change the way I structured the worksheets. Normally I would give all of my students the same problems, but this time I wanted to make sure I wasn’t leaving my higher end students bored and unchallenged. So, I took the worksheet I would normally give everyone, and added some scaffolding to make sure the majority of my regular students would be successful, and completely eliminated any extra help for my higher achieving students. For the ideal gas law worksheet, I even took it a step further and gave the higher level students more challenging problems by combining the ideal gas law with material from a previous unit. When I was reading through the final self-assessment, a few students mentioned that they appreciated having that extra challenge and actually thought of it as a review of previous concepts.

Another planning goal of this unit was to make sure the post-test focused only on the concepts we covered in class. I wanted it to be straight forward so students would know what to expect, and I didn’t want to try and trick students or have any gotcha questions.

The last thing that I think really helped students connect with this unit and stay engaged was the amount of real-world applications I included. Every time we discussed a gas law, I had students try to think of real-world examples, and then provided them with some if they didn’t come up with anything. The demonstrations gave them proof of that as well, and quite a few students had stories that related to the gas laws and gas behavior.

My main sources of evidence in the effectiveness of my planning are the self-assessment survey results: Student Self Assessments Gases Unit, and the average scores for the post-test compared to the pre-test. The most common score on the pre-test was a 0/30, as most students had zero background knowledge on the gas laws or why gases behave as they do. On the post test, the most common scores were 20/26 and 23/26. Based on those scores and the self-assessment results, I feel that my planning in this unit was effective and provided all students with the support they needed.

**Analysis of Student Work**

**Student 1: **Student 1 pre-test, Student 1 post-test. Student 1 is a female in my 1st period class. She is a hardworking student, though she doesn’t always perform at a high level. She currently has a C. She is absent quite often and comes in to get help, usually on things she missed, though sometimes for material she for which she is present. For the pre-test, she only tried to answer one question, leaving the remainder blank. This showed me that she had little prior knowledge of specific gas laws or why gases behave the way they do. She never finished the first gas laws worksheet, or at least I never checked it off as completed, but I do know that she required quite a bit of extra help in solving the problems on that worksheet. She would have problems identifying which values belonged to which variables when reading the problems, so it took her more time to work on that worksheet. She did finish the ideal gas law worksheet, with significantly less help required from me. She chose the middle level, or as I referred to them in class, the normal worksheets for both. On the post-test, she missed 1/2 a point on question 4 for using the wrong conversion factor, and 1/2 a point on question 5 for the writing low instead of high for pressure. On question 12 she rounded her calculations too much, which then caused her answer to be off. She also used the incorrect number of significant figures in her answer, so a total of one point was taken off. She lost one point on question 14 for not showing her work.

Comparing her post-test to the pre-test, as well as her work on the two worksheets, I can conclude that Student 1 was able to learn quite well throughout this unit, even though she struggled at first. This unit was effective in helping me teach Student 1 and give her the support that she needed.

**Student 2: **Student 2 pre-test, Student 2 post-test. Student 2 is a male in my 3rd period class. He is a quiet student and does not go out of his way to be an active member in class. He is present almost every day and has had a B most of the semester. On the pre-test, he attempted to answer quite a few questions, though he received no credit for any of his answers. This shows me he had little or no prior knowledge on gas laws or the reasons for gas behavior. He chose the high level worksheets and had them both checked off in class. He did not need much help on either worksheet, though he did take longer than most students in the class to finish each. On the post-test, he missed 1/2 a point on question 5 for writing low instead of high for pressure. He also missed 1/2 a point on question 12 for using the wrong number of significant figures in his answer. Those were the only points he missed on the test, which shows me that he has a very thorough understanding of the gas law calculations, as well as why gases behave as they do.

His performance in this unit shows me that this was an effective method of learning for Student 2 and he was also provided the support he needed.

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