Mass and Weight Lab

My lab consisted of the students inquiring the difference between mass and weight. The materials were simple: balance, water bottle, rubber band, meter stick, marbles, and scissors. The students were provided with a question and procedure; yet, the students were required to make inferences from the information they collected. This coincides with Heather Banchi and Randy Bell's 2008 article, "The Many Levels of Inquiry". This type of inquiry is important because it allows students to eventually develop their own abilities and conduct open ended inquiry. This is mostly seen in elementary schools, but for my seventh graders, this is on target for their ability level (Banchi, H., Bell, R., 2008). 

 It is still the beginning of the year and I want to guide the students through the levels of inquiry because up until they have me for science, they are not really exposed to any type of inquiry. I am working from the bottom up. By June, my goal is to have the students working at an open inquiry level. At this level, the students will investigate questions they formulated on their own, design their own experiment and producers and are able to communicate their inferences (Banchi, H., Bell, R., 2008). 

The procedure to the lab was as follows:

1. Cut the rubber band. Attach one end to the bottle.
2. Measure the mass of the bottle and attached rubber band in grams and record.
3. Lift the bottle using the rubber band. Measure the length of the rubber band in centimeters and record.
4. Place three marbles in the bottle. Measure the mass of the bottle with the three marbles in it and record. Lift the bottle and measure the length of the rubber band. Record.
5. Add three more marbles and repeat step 4.
6. Add three more marbles and repeat step 4.

During the mass and weight lab, the students were fully engaged. Each student took on a job in their group and worked diligently. I walked around to each group and took the time to speak with them. I would ask them scaffolding questions that related to the analysis questions in the lab. I would ask them to describe what they observed and why it was happening. From the answers the students gave, they were on track. I was very pleased with the work the students accomplished and for homework they had to finish the analysis questions. I collected the labs the next day and to my surprise the results were not what I expected.  Out of the 135 students I have this year, about 10 of them earned an 84 on the lab and 3 earned a 100. The rest of the students failed.

At first I was upset because I thought I really failed. Then I remembered...In my graduate class we were asked to conduct an experiement on global warming. We were to put ice cubes in a cup with water and see what happens as the water melts. When I came back, the water was on the table so I assumed the water overflowed from the cup, however, this was wrong. I tried the lab again and had different results. The water did not overflow the second time.

I decided to re-do the lab the following day with the students as I had down with the global

I try to recall what could of happened durning the lab with the students, but I don't know if I will ever know. I think next year I am going to do the lab the same way. If they make a mistake it is not a big deal. As long as we learn and gather the information needed, it doesn't matter what happens and we can see what our mistakes were the second time.