The Connecticut Core Science Curriculum Framework

As shown in the excerpt (Table 1) from the Connecticut Core Science Curriculum Framework Content Standards and Expected Performances – Core Science for grades 3-5 document, the state of Connecticut has included the study of light and vision for all 5^th graders. It is important to note that this is the only appearance in the K-8 Science curriculum for the study of light and vision that is required by the state of Connecticut.

Table 1.

Excerpt from Connecticut Core Science Curriculum Framework Content Standards and Expected performances – Core Science for grades 3–5. [5]

The Connecticut Core Science Curriculum Framework document is organized so that the left column is the Content Standards. These items are “narrative statements of science concepts that guide the development of a rich and rigorous curriculum.” [1] Each Content Standard includes:

In the right column are the Expected Performances. This is “the specific knowledge and abilities from the broader curriculum that will be assessed on the statewide tests given at Grade 5, 8, and 10.” [3] The 2008 CMT is the first time that students in Grade 5 and 8 will be tested for their knowledge of science content.

In addition to Content Standards and Expected Performances, students are expected to understand and use scientific inquiry, literacy and numeracy in their study of the content subject. Scientific inquiry, literacy and numeracy are considered an integral part of the content standards for each grade level. More specifically, these topics are defined in the Content Standards as follows:

Exploring Light Spectra

In this Exploration, each student built a spectroscope using a short mailing tube, diffraction grating slide, and cardboard disk with a narrow laser-cut slit.

This lesson provided the basic ideas of light essential to the understandings of all of the Expected Performances. Students were introduced to the fundamental colors of light, the visible spectrum and wavelengths and were especially thrilled to learn about ROY G. BIV. They examined the colors radiated by several unique light sources including fluorescent bulbs, gas tubes, filtered incandescent sources, lasers and LEDs (refer to photo 1). As part of their written work, students were required to complete a data table identifying the unique spectrum of each light source (refer to photo 2). By doing this, they were able to compare the light sources and speculate how the light was produced.

Photo 1.

Exploring Light Spectra Exploration – student using spectroscope.

Photo 2.

Exploring Light Spectra Exploration – student completing data table.

The highlight of this lesson was that the students were able to take their spectroscopes home. This is an important part of this lesson as the students were thrilled to be able to share the spectroscopes with their families. They not only were able to tell their families about the workshops but demonstrate and explain what they had learned using light sources within their homes. Of course, each spectroscope bore a safety label, affixed by the students themselves so they would be sure to notice, warning against looking at the sun or into a laser source. The safety label made a strong impression on the students. “Tim” wrote, “The spectroscopes we took home I used numerous times. Don’t worry, I haven’t looked into the sun.” Another student wrote, “Thank you for letting us make our own spectroscopes and take them home. I look at all kinds of lights to see what color the spectrum will be. I always make sure not to look into the sun.”

In a follow-up writing activity, students were asked to describe their favorite activity. “Kelsey” wrote “It is very hard to pick a favorite activity of the three. All of them were very fun and informative. I think the Spectroscopes was my favorite though. What I liked about Spectroscopes was how we got to build our own scopes and try different lights to see what colors make them. Plus, we got to take them home so we could use them ourselves. It was interesting how what colors you see in a light may not be what color(s) made it. Then we used a graph to record our data and see which light was the purest. The purest light has the least colors of roygbiv (red, orange, yellow, green, blue, indigo, and violet) in it when viewed through the Spectroscope. The purest light we viewed was the exit sign, which had only the color red. The least pure was the fluorescent light which had all of the roygbiv colors. My very favorite part about the Spectroscope was that I learned a lot of things I didn’t know before. At first, I didn’t even know there was anything called roygbiv or that colors unseen make the light you see. I didn’t know there was such a thing as a Spectroscope either. I also liked how the Spectroscope activity let us take part of what we learned home. I use my spectroscope all over my house now. The light over my stove in my kitchen is more pure than the one over my dinner table.”

Kelsey continues to describe the activity in more detail, “To build the Spectroscope was actually very simple. We used a cardboard tube and glued a circle of black construction paper with a slit in the middle to one side. We looked through the other side so that we could concentrate on one light at a time. Then, on the side we looked through, we looked through the grating and the tube to see lights and focus on only one of the lights. If we didn’t have the tube and slit, we’d be seeing all different lights and confusing colors through the grating. On either side of the slit, you could see the roygbiv colors that made the light you were viewing. The grating made this appear. It was very fun and interesting!”

Exploring Refraction (Jell-O® Optics)

For this Exploration, students studied refraction, absorption, and how light travels through concave and convex lenses using laser pointers and plain gelatin blocks (Knox® brand) and various colors of Jell-O® Jigglers®.

This activity is also a demonstration of how an ordinary kitchen item can be used in a scientific lab. The blocks, concave and convex lenses were cut from trays of gelatin Jigglers® made using the recipe on the box of either the Knox® or Jell-O® brand gelatin. At this point, it was also the appropriate time to introduce and stress laser safety and safe practices in lab science. In order to participate in the activity, the students were introduced to the safety instructions. Refer to Table 2 for a list of the safety rules used for this workshop. Again, background knowledge was introduced on the behavior of light rays when transmitted through lenses and different media. Students used a block of gelatin (refer to photo 3) to demonstrate how a beam of light bends when it travels from air into a medium where it travels more slowly (gelatin). In further investigation, they used concave and convex lenses cut from gelatin to show how light behaves when traveling through a lens.

Table 2.

Laser Safety Rules from “A Little Light Magic” student workshop.

Photo 3.

Exploring Refraction Exploration – gelatin block.

Students were highly engaged in this investigation because of the nature of the supplies (refer to photo 4). Vinny wrote “My favorite activity was using the lasers to see it refract in different directions off the jello.” Another student, Andrew described the activity this way, “I liked to see the light bounce right off of the jello. I also liked to learn that different shapes and angles made a difference to how the light came out.”

Photo 4.

Exploring Refraction Exploration – student using laser pointer to demonstrate refraction.

Exploring Polarization – The Magic Box and Science Journal Writing

For this lesson in scientific writing, the Exploring Polarization – The Magic Box Exploration was used. A portion of the CMT will require the students to write in a “scientific” manner which differs from the expected style of writing on other portions of the test. Short responses with “just the facts” will be more appropriate for this portion of the test. For the lesson, the students first reviewed “descriptive” writing and were required to write about an everyday object in a descriptive manner. Then writing for science was introduced with an example of describing an object with “just the facts.” Table 3 demonstrates the descriptive and scientific writing examples that were shown to the students. For this portion of the activity, the students broke into small groups and one student would write a description of an object. The other members of the small group would attempt to draw a picture of the object using the written description. Students often find writing boring, however, Brian found this lesson very engaging. He wrote “My favorite activity was the writing project because you got to write directions and someone else would try the best they could to do what you wanted. The favorite stations at the writing project was the one that you would draw a simple picture and write how to draw the picture. Then you would compare your pictures and see if they followed the directions correctly.”

Table 3.

Descriptive and scientific writing examples.

At this point the “Magic Box” was shown to the students and they were asked to describe what they saw (refer to photo 5). The students were not required to understand how polarization works as the box was the vehicle to inspire students to write scientifically. Many of the students were uncertain about what they were seeing. They were quite surprised when the instructor for this lesson passed a chopstick through the “solid wall.”

Photo 5.

Exploring Polarization Exploration – student using “The Magic Box”.

What Color is a …? Reflection of Colors

This Exploration introduces the concepts of how the eye recognizes colors, and the absorption, scattering and reflection of light. This investigation involves trying to fool the eyes with different colors of light sources. By viewing objects first illuminated by color LEDs and then in white light, participants were visually able to understand how the eyes see color. Teachers suggested additional classroom experiments based on the same principles: for example, asking students to identify brightly colored candies by viewing them under different color illumination. Although the best results were from higher priced key-tag LEDs, inexpensive LED key-tags performed acceptably.

Hit the Target: the Geometry of Reflection

This laser target “game” was adapted from similar experiments from instructional materials developed by the NSF ISE grant Hands-On Optics: Making an Impact with Light [6] and University of New Mexico Science Inquiry Through Optics [7]. To introduce this activity, participants reviewed how to use measuring devices (protractors) to quantify what they notice about reflections. For teachers, they will learn that the angle of incidence equals the angle of reflection. For some students, they may not understand the terminology but they will be able to visualize the concept. We used inexpensive plastic mirrors and protractors.

After demonstrating an understanding of this theory, the “Hit the target” game is introduced. Students will use a laser pointer and mirrors to hit a target using progressively more mirrors to add to the challenge which demonstrates their knowledge of reflection and angles. The target has a range of point values so that the students can tally their scores.

This is an important activity for students because it not only is about reflection but also is an opportunity for them to use their early understandings of angles to demonstrate how light reflects. It is also a demonstration of how to incorporate scientific numeracy into a science lesson.