No Structure Barbie Bungee – Reflection

Over the past 3 days, my Grade 8 class have been working through the popular Barbie Bungee activity. However, as I have shared in my previous post, they did it without any worksheets or guidelines. It was very coincidental that John Golden of mathhombre wrote a post challenging the worksheet approach of the activity and if an unstructured method would be more beneficial. So after 3 days and the big drops completed, I am writing the results of this first time attempt to the activity and doing it in this manner.

To start off, this activity was used as an introduction to linear relations. The goal of spending 3 days on this activity was to allow the students to generate a solution that without realizing it took into account the rate of change, independent and dependent variables, data collection and organization of data. They will compare their methods and solutions by posting them in the room. As we move through the unit the students and I will point out that they already know many of the new concepts. For example, pointing out that they already know how to calculate the rate of change, but only called it the number of centimeters each rubber band would stretch. I was worried that this final goal would not be possible due to students creating guess and check methods and estimating rather than using the necessary data. I also worried that they had no place to start, or could determine that they needed to do test trials or even consider the height of the Barbie. However, I let go and they struggled, but also came out with valuable results.

The first day was just a day of struggling (or teacher terms of practicing rigor). Given a Barbie, ruler, meter stick and 10 rubber bands my students struggled in where to start, understanding what the goal was and how they could actually get there. This was also the day of deciding what factors were important to measure. Some groups were unmotivated to do anything and decided that finding just how far 10 rubber bands would take the Barbie would be enough. I had prepared a list of probing questions and a worksheet just in case. I only gave the worksheet to 3 out of the 24 groups, but at the end of the day it was in the recycling bin as well.  The level of struggle differed between classes (I teach 4 grade 8 classes of 22 students). There were some that didn’t know where to start to others that were debating the need to measure the weight of the barbie and wanting to determine how gravity was affecting the stretch. To allow for these great discussions I now know that groups needed to be small, no larger than 3 people and with something to get them started.

To get everyone started there were guidelines to create a shared document using Google Docs and also to pick up the necessary materials. Each group identified a group leader for these tasks. By doing this it made it easier for every group to get started and everyone to have a job.

To help guide their discussions and questions I asked them to use a Question Ladder which helped them outline a potential plan of attack. By the end of the day, all but three of the 24 groups had an idea of what was going on and a plan. At the end of the day I did go home wondering if this was going to be a long few days. If I had given them the outlined instructions I would have known what step they were on and no one would have been off track, but it wouldn’t have allowed for the insight found on day 2.

Day 2 was the test drop day. By giving the groups a test height to work from also provided the struggling groups a goal and motivation. They were told the height at the start of the class and told that they could go to the drop site as many times as they wanted to test their method. To leave the room and test their method they needed to complete a proposal that had them describe their reasoning behind the number of rubber bands and also the evidence to back this up. This day was the magic day. Students left the room excited to test their ideas and methods, to return shocked that either their Barbie crashed to the floor or didn’t come close. They headed back to the drawing board to identify what they felt was the issue and come up with a new plan or make changes to their old one. Groups came back into the room sharing how close or far they had got. By doing this the groups not only engaged in friendly competition, but also they were sharing with the other groups that it was possible to get close and at least one method worked. Since no one new each others methods or plans, everyone took ownership and pride over their Barbie and calculations. Groups went back two or three times to the test drop to alter their proposals. Each time they returned to the test drop area they needed to create a new proposal and explanation using data. This made the “just add a few” or “take a few off” not an option since they needed data as evidence to back it up. By the end of the day students came back being within 2 centimeters of the floor and ready to move on. There were groups that struggled, but did not stop. They also were motivated to make changes and improve.

Day 3 looked much like day 2. The class came in, excited and eager to know their final height. The proposals from the previous day were handed out and groups retrieved their barbies. I wrote the final height on the board and handed out their final blank proposal sheets. They hurriedly got to work, writing out their methods and completing the calculations and collecting their rubber bands. I set a clock on the board indicating when the drop time would occur. The energy in the room was great as each group felt that they could be the closest to the floor. At the end of it all, the groups were working together to divide up the responsibilities and go to the drop zone. It was a great period.

Here is an example of all of the materials one group created over the three days including their final reflection sheet. 

At the end of it all, I had Barbie’s be as far away as 1.5 meters to multiple coming under the 5 centimeter goal. The final group that won was about 1-2 centimeters from the floor.

The next day (Day 4) I had the girls compare their methods, make a table of values and graph their work. The goal with this was to identify that the methods each group took were very similar, but the cause for differences resulted in how precise they collected their original data. The scatter plots of the data and showed that there was a relationship between the number of rubber bands and the distance dropped. It was at this point that I introduced the linear relations unit, the goal of collecting data and making an equation to represent that data. I also explained to them that this could have been a final test or assessment at the end of the unit and that they all have the skills necessary to do well in the unit. The goal moving forward is to ensure that they understand how the math relates to the data and the vocabulary that we use to describe it.

Looking forward, I would do this activity again next year as the introduction. Since the last day, the students have had no challenges grasping the concepts and demonstrating a good understanding of slope and rate of change. We will be preforming many more of these non-structured experiments throughout the unit and it will be interesting to see what they learned and will improve on each time.

For my IEP students I feel that they would have done better in this type of activity than in a structured one, contrary to my Spec Ed. training. I think that by giving more structure and steps, students can see it as being more places that they could mess up on and feel that they can not continue without the support of a teacher. In this method it looked like just one problem that I only had to give them support at the start and the rest was just a continuation of this.

If you have other great activities for linear relations I would love to hear of them and try them out in a similar manner. I also want to improve on how I am using the results of the activity moving forward. We did the Day 4 summary, but as we have gone ahead, I am finding it challenging to see how I can connect the material back to the activity without the standard “Look, rate of change is just like the number of elastics”. This might be the extent to it, but any suggestions would be great!

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One Response to No Structure Barbie Bungee – Reflection

  1. Thanks for sharing your worksheets, guidelines and questions.
    I wonder if like all things the more practice students get at working in an unstructured environment the easier it becomes. The learning is slower and harder to measure but arguable deeper and longer lasting. Great stuff!

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