The Case of the Invisible Signal

Learning Resource Type

Lesson Plan

Subject Area

Science

Grade(s)

9, 10, 11, 12

Overview

Are cell phones really safe for humans to use frequently? In this mock trial lesson, students will use claim, evidence, and reasoning to construct a scientific argument on the safety of the electromagnetic waves involved in cell phone technology. During the lesson process, students will hold a “trial” and each individual student will construct their own written “verdict” based on the evidence presented at the mock trial.

This lesson results from the ALEX Resource Gap Project.

Science (2015) Grade(s): 09-12 - Physical Science

SC15.PS.14
Propose and defend a hypothesis based on information gathered from published materials (e.g., trade books, magazines, Internet resources, videos) for and against various claims for the safety of electromagnetic radiation.

Vocabulary

Electromagnetic waves
E/M spectrum
Visible light
Microwaves
Frequency
Radio frequencies
Video terminals
Magnetic fields
Internet resources
Ionizing radiation
Non-ionizing radiation
Wavelength

Knowledge

Students know:

Electromagnetic radiation (e.g., radio, microwaves, light) can be modeled as a wave pattern of changing electric and magnetic fields or, alternatively, as particles.
Electromagnetic radiation may be ionizing or non-ionizing type. Non-ionizing type of radiation is used in common electronic devices.
Non-ionizing type of radiation is used in common electronic devices.

Skills

Students are able to:

Identify types of electromagnetic radiation.
Select credible resources from the Internet and AVL for use in the argument.
Categorize electromagnetic radiation according to safety levels for humans.
Cite specific textual evidence to support analysis of science and technical texts.
Determine the central ideas or conclusions of a text; trace the explanation or depiction of a complex process, phenomenon, or concept; provide an accurate summary of the text distinct from prior knowledge or opinions.
Engage in argument from evidence on the safety of electromagnetic radiation.

Understanding

Students understand that:

Non-ionizing radiation, such as those emitted in electronics, cannot cause immediate damage, but does interact with the body to potentially cause indirect damage, following long-term exposure.
Ionizing radiation, such as X-rays and gamma rays, can be hazardous.

Scientific and Engineering Practices

Engaging in Argument from Evidence

Crosscutting Concepts

Cause and Effect

Primary Learning Objectives

The students will describe the electromagnetic spectrum and its properties.

The students will describe how energy from electromagnetic waves is transformed once it hits matter.

The students will prove a prediction (hypothesis) based on research. (Note: Since the students are not completing an actual experiment on the topic, an experimental hypothesis and null hypothesis in this lesson are simply the predictions that the prosecution and the defense will "prove" during the trial.)

The students will use research, writing, and the mock trial format to deliver technical information regarding the safety of the electromagnetic waves used in cell phone technology.

The students will use claim, evidence, and reasoning to answer the question: Are cell phones really safe for humans to use frequently?

Additional Learning Objective(s)

I can describe the electromagnetic spectrum and its properties.

I can describe how the energy from electromagnetic waves is transformed once it hits matter.

I can compare and contrast the electromagnetic waves used in cell phone technology with other types of electromagnetic waves.

I can use claim, evidence, and reasoning to answer the question: Are cell phones really safe for humans to use frequently?

Procedures/Activities

Before Activity/Engage: (Approx 15 minutes)

Create a poll for your students to answer when they enter the classroom. Ask them the following question: Are cell phones safe for people to use frequently? You can do this on a simple presentation slide if each student does not have access to a device or a Google form like this one. Use a show of hands to tally the vote or you can use an app like Plickers to collect answers anonymously. If your school is one-to-one, create a digital poll using Survey Monkey or Google Forms. Then, you can show the students the results using a graph to reinforce data skills. For these digital sources, the graph is automatically created. However, if you use a show of hands, you can draw a pie chart on the board or generate a pie chart using Excel or another spreadsheet software. Discuss the results with students using follow-up questions such as: Do these results surprise you? Why or why not? Why did you answer yes? Why did you answer no?

Then, show the students this video on the safety of cell phone use or another video of your choice that discusses the safety of cell phones and radiation use.

After the video, use questions to activate the students’ prior knowledge of the electromagnetic spectrum and energy. Some sample questions would be: What type of electromagnetic wave is used in cell phone technology? What typically happens when energy travels into a different medium? Can types of electromagnetic waves travel inside the body? How do we know this? Is frequent contact with electromagnetic waves safe or harmful to the body?

Lesson setup (10 minutes): Explain to students that they will perform a mock trial to determine the answer to the question: Are cell phones safe for people to use frequently? Divide students into two groups: the prosecution and defense. Then, pass out the individual research pages, mock trial roles for the Case of the Invisible Signal (for group role responsibilities), and the mock trial role rubric. Go over each handout with the group by reading the entire handout in class (individually or whole class) and highlighting the superior criteria on the rubric. You may ask students simple questions about the handout as you discuss it in class to ensure comprehension of the handouts. When you are going over the handouts, be sure to also note the roles that each plays in the trial format. Tell them that they will choose their roles in their group later. You may want to give each group a folder so that they can keep their handouts safe during the entire lesson. During this part of the lesson, be sure to explain to students that their job is to prove their group's prediction or hypothesis regarding the safety of cell phone use. For the prosecution, the prediction or hypothesis will be that cell phones ARE NOT safe for people to use frequently. For the defense, the prediction or hypothesis will be that cell phones ARE safe for people to use frequently. Let the students choose the individual roles that they will play in their group OR assign roles based on your knowledge of the students. Be sure to note that the prosecution will always present FIRST and the defense will always follow the prosecution.

During/Explore/Explain: (Days 2-4 on Period Schedule OR Hours 2-5 on a block schedule)

Explain that first, the students need to gather information on the safety of cell phones to help their groups create their “case”. Tell them that they will begin their research using carefully chosen sources and place their research in their Individual Research Page (see attachments). Be sure that you note the deadline for their individual research page. If using only digital sources, send the digital sources to each student online. Sample digital sources are provided in the technology section. If using paper sources, pass out the copies of the chosen resources to each student. Give students time to research cell phone safety using your provided sources. This should end the first hour of class. Use the last 3 minutes of class (for a 55 minute period) to have each student complete a quick exit ticket: What are three facts that you have learned about cell phone safety in your research today? See the presentation in the attachments section. You may create a ticket handout with this question if you have the resources to make copies. However, to save copy resources and materials, students can simply answer this question on notebook paper. View these documents to determine if students are struggling to comprehend the provided resources and address any misconceptions with the students during the next class.

At the beginning of the second hour, tell each group that they should begin to discuss how they will set up their “case”. Have each group determine the group role for each group member. Then, have the students determine what kind of expert witnesses that they will need. As a group, the students need to determine where they have holes in their research and they should search for additional resources. Be sure to remind students how to search for reliable resources so their information can be used as evidence. All additional research should be added to their research page. Before the end of class, the teacher should meet with each group to discuss their research and how they are going to approach the delivery of their case. Each meeting should take 5 to 7 minutes and the meeting can be used to redirect misconceptions and help guide students to make a better argument.

At the beginning of the third hour, each group will write their opening arguments and determine their line of questioning. Give each group the CER handout, so that they can review the criteria for making a scientific argument. They will also give the names and background of each of their “expert witnesses” to their opponent group so that they can determine questions to ask during the rebuttal of their opponent’s expert witnesses. The "expert witnesses" should be created from information gathered during research. Remind the students that they should be asking: What types of experts would be useful to defend our argument at trial? Have the students use creative names and titles to help illustrate the expert characters that they create. For example, a ninth grade high school student would not be an expert on the science and safety of cell phone signals. At the end of class and during class, the teacher should circulate and meet with each group to determine progress and redirect misconceptions. Be sure to remind each "lawyer" to be prepared for their opening statements during the next class or the 4th hour (if you are on a block schedule).

At the beginning of the 4th hour, give each group 5 minutes to complete the final organization of their opening arguments. The trial will begin with the opening statements of the prosecution first and then defense. Each opening statement should take about 5 minutes. Then, the prosecution will present their case. During the trial, each student should take notes on the material presented at trial to be used during their CER writing. You can give them a specific note-taking format like Cornell notes if you like, or the students can just take simple jot notes. You can end this day’s trial by making each student write a short newspaper “article” summary as an exit ticket. See the presentation attachment for the instructions on how to do the simple "article".

After/Explain/Elaborate: At the beginning of the fifth hour, the defense will present their case. Students in the class will take notes to be used during their Individual CER writing. Each group will give their closing statements. Then, each individual student will take the exit poll, which is the same as the entrance poll. Determine if the class data changed and how it changed. Ask follow-up questions to determine why the data either changed or remained the same. Finally, have each individual student do an individual CER writing that will be used as a summative assessment. You can use the handout provided in the attachments OR have the student simply write it in the format on their own paper. Use the CER rubric to grade the writing.

Note: As discussed in the NSTA and ADI resources, the CER presentation is initially done in groups under a typical argument-driven inquiry activity. However, the format of this activity bypasses the group CER presentation because the group argument is presented with the trial. Thus, the final sentence of the assessment should be ignored for this activity but can be used in other CER activities.

Assessment Strategies

Formative assessment: entrance poll, exit poll, whole group questioning (as the teacher circulates the room), group interview (with the teacher during class), research page (see attachments for the handout), exit tickets (See attachments for The Case of the Invisible Signal Exit Ticket Presentation).

The entrance and exit polls will give the teacher an idea of how student opinions have changed based on their research and the trial. During the class, whole group questioning can be used to check for comprehension of the lesson and the format of the lesson as well as the documents and rubrics used in the lesson. In addition, the group interview will allow the teacher to give feedback on the presentation of the argument before it goes to trial and identify misconceptions or weaknesses that can be addressed before they are presented at trial. The research page should give the teacher an idea of what sources were used, their credibility, and the students' comprehension of their sources. Finally, the exit tickets will give the teacher an idea of what the students are absorbing from the presentation and any misconceptions that the students may have generated based on the presentation of the material at trial.

Summative assessment: CER writing graded with rubric and group role performance graded with rubric.

The CER writing will directly assess the student's ability to answer the question (Are cell phones safe for humans to use frequently?) and their ability to back up their claim using scientific sources. The group role performance will summatively assess the students' participation and completion of their group role.

Note: As discussed in the NSTA and ADI resources, the CER presentation is initially done in groups under a typical argument-driven inquiry activity. The group designs an argument, and they present it in round robin format. However, the format of this activity bypasses the group CER presentation because the group argument is presented with the trial. Thus, the final sentence of the CER rubric assessment should be ignored for this activity but can be used in other CER activities.

Acceleration

Students who need additional challenges on this topic can create a Public Service Announcment video on the safety of cell phone use to present on the school website or on YouTube. A public service announcement is like an advertisement that informs the public on a particular topic, which usually involves health issues.

Intervention

During research, students who are still struggling with basic concepts on the electromagnetic spectrum or who need additional assistance with close reading sources can be pulled for small group instruction or individual help by the teacher.

Total Duration

Greater than 120 Minutes

Background/Preparation

Before you start the lesson, the students should be familiar with the electromagnetic spectrum, its properties, and its uses in society. Some excellent resources to use to teach the general properties of the electromagnetic spectrum include the following: NASA video and the NOVA interactive. The students should also be familiar with citing resources and choosing credible resources.

The teacher and the students should be familiar with the general format of a trial. The following resources provide some information on the mock trial format and how it should be presented: The New York Times Learning Network Blog and Read Write Think. Remember that the lesson objectives refer to the safety of cell phone use NOT the mock trial format. Be careful and avoid letting your focus be more on the mock trial format instead of the collection of information on the safety of cell phones and the use of scientific claim, evidence, and reasoning.

The teacher and the students should also be familiar with using claim, evidence, and reasoning to form a scientific argument to answer a question. For more information on developing a scientific argument, you may find the following resources useful: Argument-Driven Inquiry website and NSTA presentation on CER.

Also, prior to any lesson, the teacher should also check all links to videos and sources to ensure that they will open and play on school devices connected to the school network. If not, all sources should be saved or presented in another manner to ensure that the lesson runs smoothly.