Lesson Analysis
My goal in teaching this lesson was to engage my students in a discussion of their observations of both the structure and function of the hermit crab’s shell and of the hermit crab’s habitat. Overall I think my students really enjoyed participating in this lesson, as they were extremely engaged throughout the whole thing. I also think that they truly learned something. I think that they left with an understanding of 1.) the structure and function of the hermit crab’s shell, 2.) the meaning of the word ‘habitat,’ and, 3.) perhaps to a somewhat lesser extent, what it means to observe using all 5 senses.
Assessing Student Understanding-Habitat
One of the first things I did was ask the students if they thought they might know what the word ‘habitat’ meant. I was unsure of whether any of them would be familiar with the word, so I was prepared to be able to define it as ‘a place where a plant, animal or person lives—its home or environment.’ While the first student I called on was not sure, the second student, Ben, responded with an answer that used the word ‘home,’ stating confidently, “A habitat is like when somebody build their own home and they live in it forever and never leave it unless it broke.” This was an answer I was not expecting and I was thrilled to be able to start the lesson by showing students how much they already know and how capable they are of thinking like scientists. Furthermore, because I could tell that two of my students were not paying attention and did not hear Ben’s definition of habitat, I asked if there was another student who thought they could tell the group what a habitat was. This student responded by saying, “It’s a home,” and yet another student added that a person’s habitat would be “a house.” So just a few minutes into the lesson I felt that a number of my students had a good understanding of the meaning of the word ‘habitat.’ (Unfortunately the video of the first few minutes of the lesson is not clear because my classmate was trying to find the best way of positioning the camera, but the audio was good enough that I was able to transcribe what happened.)
My Penn Mentor's observations.
Later in the lesson I asked students to make some observations about the hermit crab’s habitat. At first they responded by telling me more about the hermit crab itself. One student, for example, said, “I saw its face and eyes.” I reminded them that we were focusing our observations on the hermit crab’s habitat, and immediately this student corrected herself, exclaiming, “Oh, its shell! It lives in a shell.” Another student stated, “Some can live on the beach,” and when I prompted her tell me what in the hermit crab’s habitat she noticed that looks like a beach she identified the sand. Yet another student identified that there was food and water in the habitat.
Assessing Student Understanding-Structure and Function of Shell
When I took out one of the hermit crabs and held it in my hand I asked the students to tell me something they already knew about hermit crabs, something they noticed about the hermit crab in my hand, or something they were wondering about hermit crabs. Each student got a chance to share. Once again, I was extremely impressed with the amount that some of them already knew. Between the seven of them they told me that “they hide in their shells,” “they crawl around/move,” “they pinch,” and one student wondered, “Do they bite?”. Zakhiyyah said, “I know that he gonna try to get in a new shell when he grows and gets big,” which told me that she had likely learned about hermit crabs somewhere else. Zakhiyyah’s answer gave me the perfect segue into a discussion about the hermit crab’s shell and its structure and function. I made a decision to build on her answer by giving the students some more information. I told them that a hermit crab’s shell is not actually attached to its body, that it’s separate. In my lesson plan I had originally planned to also tell them that the shell protects the soft body of the hermit crab. However, given how much my students seemed to already know and how interested in and excited they were about sharing their thoughts and ideas, I decided to deviate from my plan and instead ask them if they knew why hermit crabs have shells. The first student I called on replied, “They hide in their shells.” To get them to think deeper, I followed up by saying, “Yahnira just told us that sometimes they hide in their shells. Why would they need the shells?” Below is a video of their responses to this question, all of which demonstrated a good level of understanding. The first student suggests that the shell keeps the hermit crab warm. The second states his new understanding of the fact that the hermit crab will move into a bigger shell when it grows, and the third student says, “to protect it.”
Later in the lesson I was given an unexpected opportunity to assess my students’ understanding of the structure and function of the hermit crab’s shell. One of my students, Ben, was pulled out of the room in the middle of the lesson by his sister, who unfortunately decided it would be a good time to stop by and reprimand him for something he had done earlier. He started crying in the middle of my lesson, so I let him go get a drink of water with my Penn Mentor. When he came back in I decided to ask the rest of my students if they could tell Ben what we had been looking at and talking about. At the time I was showing them a photograph of a hermit crab without a shell. Below is a video of their explanations for Ben.
They were able to explain that we were looking at a photo of a red hermit crab’s body, and that the body is soft. One of the students pointed out the part of the body that would go inside of the shell if the hermit crab were to crawl into a shell.
Assessing Student Understanding-Observation
The chart I used to record their observations
Of all my lesson objectives I am least sure of how well my students understand what it means to observe using all five senses. They seemed to be most naturally inclined toward using their seeing and touching senses in this experiment. This makes sense and is not surprising given the nature of the lesson, however I wish that I had made a point to encourage the use of the smelling and hearing senses as well. Not one of them generated an observation using the smelling or hearing sense. That being said, the observations they made using their seeing and touching senses were very appropriate and thoughtful. One of them noted, for example, that the hermit crab’s shell felt hard and cold. Additionally, they observed that the sand felt like ‘sugar’ and ‘salt,’ and that ‘it’s a little soft and a little hard.’ While I was originally confused about how something could be both soft and hard I actually understand this sentiment! When you run your hands over a bunch of sand it feels quite smooth, but if you grind the sand in between your fingers it feels rough. I find this to be a very astute observation.
Observer Notes
These notes were taken by my Penn Mentor during my lesson.