Show Me the Genes: Making Posters to Communicate Solutions

Many brilliant engineering designs are never realized or are delayed for decades, not because of error or unreliability of the design, but because they were not adequately disseminated to the larger production and consumer marketplace. If engineers are to succeed at designing successful products, they must be able to design the products AND successfully communicate their effectiveness and usefulness to companies and individuals who have the means of bringing them to manufacture and distribution. In this activity, students practice communicating ideas effectively by using a poster format to logically and cohesively present their solutions for gene detection in a way that people unfamiliar with the topic can be convinced of their value.

After this activity, students should be able to:

• Explain thin film refraction and the factors that influence it.
• Illustrate thin film refraction in an accurate diagram.
• Explain the experimental results of using an optical biosensor, and prove these results with a mathematical example.

Students must have:

• A complete understanding of the unit's challenge question.
• An understanding of optical thin films, including refraction and interference.
• The ability to solve problems using Snell's law.

Today is the day you get to show off what you know! We have learned a lot over the past few days. We started with a challenge question that we knew nothing about, and have brainstormed about the topic (Generate Ideas), brought in outside sources from the scientific community (Multiple Perspectives), and even performed our own experiments with refraction (Research and Revise) to see how we could use refraction and thin films to solve the challenge. We even learned and practiced using equations to prove that refraction works in the form of a biosensor (Test Your Mettle).

Now that we know a solution to the challenge question in all its details, we are ready to publish our work, and bring our wonderful idea to the community in the final phase of the Legacy Cycle, Go Public. To do so, each group will create a poster outlining its device, how it works, and all the relevant physics concepts that enable it to work. You will even get to brainstorm within your group to decide how you want your optical biosensor to look! You will prove the worthiness of our method by giving specific examples, complete with equations to make sure everyone who reads it will understand our work, and its validity.

To guide you, use the requirements & rubric handout; it details what to include on your poster and how to organize it. Take a look at your copy of the rubric; notice all the relevant information, including point values for the sub-components of the assignment. To make sure everyone understands, let's go over it briefly, and then I'll let you get started!

Background

This activity functions as part of the summative assessment for this unit, contributing to the last phase of the Legacy Cycle, Go Public, during which students present the results of their work. Student groups create posters that depict their solutions to the unit's challenge question— how optical biosensors might work to detect specific genes.

Before the Activity

• Student groups should each have a copy of the Presenting the Optical Biosensor Poster Requirements & Rubric (PDF), as handed out in the associated lesson; but if not, make replacement copies, as needed.
• Gather materials.
• (optional) Make an example poster to show students or have one handy one from a previous class.
• (optional) Reserve a computer lab with a printer for students to find and print images.

With the Students

1. Present the Introduction/Motivation content to the class.
2. Have students gather at tables or work spaces in their groups of three. Give each group one poster board and poster-making supplies: scissors, glue, colored paper.
3. Ask students the pre-activity questions, as explained in the Assessment section and listed in the Investigating Questions section. Walk through how what they learned in the previous lessons and activities of the unit could be sequenced and presented on a summary poster. Emphasize the importance of being organized and logical in presenting information to the poster reader. Recall from the associated lesson tactics they can use to ensure a quality presentation of research results.
4. Go through the requirements & rubric document in detail, outlining what students are expected to do

• Show them an example poster.
• Answer any question, and make sure all students understand the assignment.
• Be sure to include the role of the challenge question in the discussion, making sure students understand the challenge question and this activity's connection to it.

Challenge question: "In 2013, actress Angelina Jolie underwent a double mastectomy, not because she had been diagnosed with breast cancer, but merely to lower her cancer risk. But what if she never inherited the gene(s) that are linked to breast cancer and endured surgery unnecessarily? Can we create a new method of assessing people's genetic risks of breast cancer that is both efficient and cost-effective?"

5. Inform students that in order to receive full credit for the "illustrations" portion of the rubric, posters must include drawings and/or diagrams that depict their own concepts of what their optical biosensors would look like. This tends to be difficult for students, so make sure they understand that it is purely conceptual! They do not need to build or test their devices (like real-world engineers would do), just draw one possibility for what it could look like. Full credit is derived from labeling the following: how the solution/DNA gets into the silicon, and how the reflected light is "captured" or "seen" when the phase shift occurs.
6. Have student groups assign team member roles as such: technical consultant (to make sure information presented is accurate and complete, and create rough-draft illustrations), graphic designer (responsible for pleasing and effective layout and readability of poster, illustrations and images), and editor (to type or hand-write text and equations, helping to place them on the board for logical flow of information, and making sure that poster requirements are met). Remind groups to brainstorm as a team to determine how they want their biosensors to look.
7. Give students the rest of the class period to work on their posters. Monitor their progress and answer questions. If class time is insufficient, permit students to work on their posters outside of class time, completing them by a specified due date.

Pre-Activity Assessment

Review Questions: Review the previous three lessons and associated activities with students, posing the Investigating Questions to the class. Gauge the proportion of correct responses before moving on.

Activity Embedded Assessment

Poster Perusing: During the activity, monitor student poster-making progress for organization, clarity and accuracy. Address any errors that reappear from group to group with the entire class. Help them through any stages of feeing stuck or overwhelmed.

Post-Activity Assessment

Poster & Quiz: Grade the team posters using the Presenting the Optical Biosensor Poster Requirements & Rubric (PDF). Then, together with students' individual quiz results from the associated lesson, assess student learning for the entire unit as well as this concluding lesson and activity.

• If a computer lab is available for students to find and print images, make sure the messy gluing and cutting are permitted in the lab. If not, provide a suitable space for students to perform these activities away from the computer equipment.

Students often have trouble getting started, since the poster includes so much information. It is helpful to review the sequence of lessons that comprise this unit to give them some structure, as well as hints to jump-start their creativity.

• For lower grades, require less detail, or remove the mathematical example portion of the rubric.
• For upper grades, require more detail, such as an explanation of how light could be applied to the sensor, such as lasers turned at specific angles.

Klein, Stacy S., Harris, Alene H. "A User's Guide to the Legacy Cycle." Journal of Education and Human Development. Vol. 1, No. 1, 2007. http://www.scientificjournals.org/journals2007/articles/1088.pdf