This activity is part of the Germ Problem-Solvers: Using Engineering to Develop Solutions unit.


1. Lead students in observing high-touch areas so they can use data to inform their solutions.
  • Provide students with a list of the contexts and problems discussed in the Invisible Villains activity, compiled from their Spreading Germs Snapshots handout. Have students pick a context or specific problem to solve. Organize students in project groups of three or four based on the problem or context they are interested in working on. Students will work in these teams to design a collaborative solution as the final product for the unit project.
    • Contexts could include: times of day, situations, or locations when germs are spread (e.g., riding the bus, lunchtime, recess, etc.)
  • Problems could be specific issues in their context that need to be solved (i.e., the restrooms are out of soap, friends don’t cover their coughs, friends share drinks at lunch, some people come to school when they are sick, etc.).
  • Point students to the preliminary predictions they made about high-touch, germy areas after watching the video Growing Bacteria (2:11) by Sick Science!, in the activity Getting to Know Germs.
  • Let students know that in this lesson, they will carry out some observations of those high-touch areas to see if their predictions are correct.
  • Using their list of high-touch areas as a starting point, narrow the areas down to three or four locations that could be observed easily in five to ten minutes.
    • For example, a water fountain, the doorknob to the restroom, a highly-trafficked railing on the way to lunch or activity, your desk, etc.
    • Distribute the Observing Germy Places handout and model for students how to use tally marks to keep track of how often a surface is touched in the determined time frame.
    • Observe each location as a class or, if you have other adults to help, divide the class into three or four groups to carry out the observations. Regroup to share and discuss the class findings; direct students to record the findings from other groups on their data table and determine which location was touched the most.
    • Assist students as they write a claim on their handout. Explain to students that a claim is a statement you make based on evidence that answers a question. Share the question we are answering with this activity: Which area in our school is the most germy?
    • Have students work in their project groups to use evidence from their observation to make a claim about which location is the most “germy” and what behaviors cause that location to have a lot of germs. (Sample student response: For our solution, we will focus on the walls along the hallway to the lunchroom. We observed 11 out of 19 children running their hands along the walls. They were on their way to lunch. This makes this location very germy. Now they are eating with germy hands! They could get sick!)


2. Introduce the next step of the engineering design processimagine possible solutionsas well as example solutions to prepare students for brainstorming.
  • Remind students of the driving question of the lesson (How do we keep germs from spreading?), the final product of the unit project (to design a tool or product that helps keep germs from spreading), and the problem(s) they are trying to solve.
  • Introduce the next step of the engineering design process using the Engineering Design Process Cycle Graphic—imagine possible solutions.
  • Before students begin brainstorming, show existing examples of designs or products that are intended to slow the spread of germs that make us sick. Some examples include:


3. Lead students in brainstorming solutions to germ-spreading problems they identified in previous activities so that they can make progress on their final product.

  • Introduce guidelines for collaborative brainstorming, such as:
      • Everyone gets a turn to share
      • Record all ideas
      • Build off of each other’s ideas
      • Encourage wild ideas and spontaneity
      • There are no wrong ideas
      • No talking over each other
      • Respect each other’s ideas
      • Stay focused on the topic and keep the problem in mind
      • Develop as many ideas as you can
  • Distribute and introduce the Brainstorming Solutions handout they will use to collect their ideas.
      • Be sure that students also have access to their Getting Rid of Gross Germs Research Notes handout and Spreading Germs Snapshots handout.
  • Remind students of the driving question for the unit and of the limits to solutions they discussed in the Getting Rid of Gross Germs activity and recorded in the Getting Rid of Gross Germs Research Notes handout.
  • Ask students to identify the specifics about the problem they are solving (who/what/where/when/why) on their Brainstorming Solutions handout.
  • Ask students to brainstorm and record as many solutions as possible in their small group for their assigned/chosen context or problem.
      • Explain that the purpose of this step is to come up with solutions to the limits students described in the last question of the Getting Rid of Gross Germs Research Notes handout and solutions to the problems pinpointed in the Spreading Germs Snapshots handout.
  • Remind students where they are headed in the unit. They are brainstorming ideas today, and they will choose one of these solutions and design it later. Therefore, they should not get too bogged down in considering materials or constraints in this brainstorming session.
  • After 10-15 minutes, come back together as a whole class to discuss the process. Prompt students to reflect on the challenges and benefits of their group’s brainstorming process.
  • If time allows, prompt students to share some of their initial ideas with the whole class.
  • Let students know that in the next activity, Developing Our Germ-Stopping Solution, they will be working on selecting promising solutions.

Informal Assessment

Class Discussion: Use class discussions to assess students’ ability to participate in collaborative conversations and understanding of how to identify specific problems and solutions.

Brainstorming Solutions: Use the brainstorming solutions handout/brainstorming discussions in small groups to evaluate students’ ability to follow agreed-upon rules for discussions and build on others’ talk in conversations as part of the engineering process.

Extending the Learning

If you want to spend more time discussing and modeling the brainstorming process, use this PBS Kids resource, Brainstorm.

Subjects & Disciplines

  • Biology
    • Health
  • Engineering

Teaching Approach

  • Project-based learning

Teaching Methods

  • Brainstorming
  • Discussions
  • Inquiry

Skills Summary

This activity targets the following skills:

Connections to National Standards, Principles, and Practices

Common Core State Standards for English Language Arts & Literacy

What You’ll Need

Required Technology

  • Internet Access: Optional
  • Tech Setup: 1 computer per classroom

Physical Space

  • Classroom


You may want to have students choose their problem or context during the previous activity, Getting Rid of Gross Germs, so that you can organize students into their project groups before this activity begins.

Students will work in these groups of three or four for the rest of the unit to collaborate on a solution to their chosen problem.


  • Heterogeneous grouping
  • Large-group instruction
  • Small-group work

Accessibility Notes

Step 2: Provide students with three to four minutes to brainstorm individually before working in groups to provide all students a chance to bring ideas to the group.

Background Information

The engineering design process is a series of steps that engineers go through to solve a problem. The third step—imagine possible solutions—includes brainstorming ideas with a group. In this activity, students collaboratively brainstorm several solutions for how to stop the spread of germs to solve a specific problem for a specific context. Undertaking authentic professional practices in the science classroom (such as the engineering design cycle in this activity and throughout the Germ Problem Solvers unit) are crucial ways in which students can develop a broadened sense of what it means to be a scientist or engineer. Explicitly highlighting how students’ classroom activities are the same as professional practices can foster their identification with science and engineering, leading to students’ ability to “see themselves” as scientists or engineers, and even increase their desire to pursue STEM disciplines in college or career pathways. Further, encouraging students to bring in their ideas about how they use science and engineering in their everyday lives provides the final link to holistically expand their sense of these subjects as taking place in many different contexts, not just in the classroom.

Prior Knowledge

  • None



to discuss a problem and suggest solutions or ideas


set of facts having to do with a specific event or situation.

engineering design process

series of steps that guides engineers as they solve problems.


an answer to a problem.


a recorded number of items.