The Case of the Invisible Signal

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.