Analog World, Digital World: Encoding and Transmitting Information

Annie Haven and Chatham Marconi
Type Category
Instructional Materials
This resource, vetted by NSTA curators, is provided to teachers along with suggested modifications to make it more in line with the vision of the NGSS. While not considered to be "fully aligned," the resources and expert recommendations provide teachers with concrete examples and expert guidance using the EQuIP rubric to adapted existing resources. Read more here.



The “Analog World, Digital World” unit is comprised of plans for six days of lessons.  Over the course of this lesson set students will be arguing the “merits and limitations” of various devices that operate with digital and analog signals. This unit also has a performance task that allows students to demonstrate what they have learned over the course of this six day unit. Over the six planned days of this units students will complete the following tasks.  Students will analyze, reproduce, encode, and transmit analog information. Students will also develop an understanding that digital signals use a 0/1/off /on code format.  They will also compare analog and digital devices performing various tasks. Finally, students will graph and interpolate digital sound wave data.

Intended Audience

Educator and learner
Educational Level
  • Middle School
Access Restrictions

Free access - The right to view and/or download material without financial, registration, or excessive advertising barriers.

Performance Expectations

MS-PS4-3 Integrate qualitative scientific and technical information to support the claim that digitized signals are a more reliable way to encode and transmit information than analog signals.

Clarification Statement: Emphasis is on a basic understanding that waves can be used for communication purposes. Examples could include using fiber optic cable to transmit light pulses, radio wave pulses in wifi devices, and conversion of stored binary patterns to make sound or text on a computer screen.

Assessment Boundary: Assessment does not include binary counting. Assessment does not include the specific mechanism of any given device.

This resource is explicitly designed to build towards this performance expectation.

Comments about Including the Performance Expectation
This unit can be used to have students explore analog and digital signals that are present in their daily lives. Linking student background knowledge early in the process will be helpful over the course of the unit. Students will understand the difference between digital and analog signals, use mathematical graphs to see the difference, and use their senses to understand the difference between the two signal types. The lesson culminates with a persuasive, or claim-evidence-reasoning, writing piece.

Science and Engineering Practices

This resource is explicitly designed to build towards this science and engineering practice.

Comments about Including the Science and Engineering Practice
To be more intentional with this practice it is suggested that the culminating writing assessment be slightly modified to a Claim-Evidence-Reasoning model. As it is written, students spend first two days learning about digital and analog signals. After the initial two day overview having students make a claim based upon their present understanding would add more intent to the evidence collection during days three through five. Students could make an evidence chart where they could record their data and observations . By making the evidentiary days more intentional the students will collect better data. There will be a stronger purpose to the middle three days. The unit has a well done data sheet for the two day station activity, and adding to this would enhance the practice. A final suggestion is to have students use data and observations collected to compose a reasoning response and incorporate that into the final activity. The final activity has students choose digital or analog signals for music if they were a recording artist. Adding a specific science reasoning part to this literacy activity would serve as a nice way for students to not just state what they feel is best, but to anchor it to actual science seen and measured during this unit.

Disciplinary Core Ideas

This resource is explicitly designed to build towards this disciplinary core idea.

Comments about Including the Disciplinary Core Idea
The DCI is well established within the lesson. Students are able to compare analog and digital systems at various parts of the unit. The station comparison, the graphing activity, and the music homework sheet offer the students a number of opportunities to not only compare, but to see how digital signals are a more reliable way to send code. The graphing activity specifically, is a clear method to drive the DCI in this lesson set. This unit has a six day schedule, and it can be modified to five days if the station activity is condensed into one day. Having students generate the pace of this unit would allow them to have more voice in the lesson, share more of their background knowledge, and make more connections as they gather data and observations.

Crosscutting Concepts

This resource is explicitly designed to build towards this crosscutting concept.

Comments about Including the Crosscutting Concept
Signals are the sole focus of this unit. As student spend the first two days looking at analog and digital signals it is suggested that the students create some form of visual representation of the two types of signals. An individual side by side chart, or a large one for the class to use together, to display visual representations of digital and analog signals would benefit the students in seeing the patterns of both digital and analog signals. The chart would also be beneficial to students as they write reasoning statements. The visual aspect that charts would establish, would benefit multiple parts of the unit.

Resource Quality

  • Alignment to the Dimensions of the NGSS: The unit being reviewed has components to each dimension of the NGSS standards. The practice of argumentation is a focal point in the later stages of the unit. Students have to use evidence seen and observed during the initial stages to debate the reliability of digital and analog signals. The practice connects to the core idea of the reliability of digital signals. As students work through the stations they are comparing digital and analog signal devices. This direct activity will show them the reliability of digital signals. The energy concept is also woven into the station activity. Students will see the energy that signals have and how the two types of signals are different. The only component that this unit lacks is one overlying graphic organizer for students to keep track of not just data, but of the three dimensions. As mentioned in the Practice section earlier, converting this unit to a Claim-Evidence-Reasoning unit would enhance not only the practice, but the way the three dimensions work together. A day to day graphic organizer for students to chronicle their work, create questions, and formulate scientific reasoning would enhance this resource.

  • Instructional Supports: This resource is also contains three dimensional resources for students to complete. These resources are being utilized both in class and outside of class. For each lesson there is a homework piece that ties ideas together, analyzes data, reinforce data, or gives students a platform to question. Question eleven on the “Analog World, Digital World Graphing Homework” give students the opportunity to think about what they have seen and generate new questions at the midpoint of the unit. That same homework assignments has the students plotting graphs, and then comparing them. Those types of three dimensional connections are woven throughout the unit. The plans that accompany this unit are very detailed. They include links to videos, Day 1 and 2, and animations, Day 2. Teachers using this resource need to read over the plan in advance to be able to be intentional with the use of the online resources. These components are key to the three dimensional nature of the resource and should all be made use of during unit implementation. Differentiation supports are also included in the lesson plan and in the homework sections. These suggestions allow for differentiation for remedial and advanced learners.

  • Monitoring Student Progress: This unit offers opportunities for teachers and students to monitor their progress. The daily homework connects and extends the student's knowledge. Reviewing the homework prior to moving on would be a good way to see if the students are at the point to move forward. In the plan for Day 1 there is a “Think, Pair, Share” can act as a strong opening formative assessment. The unit does not specifically stipulate formative assessments, but there are select parts of homework assignments that could be used as formative assessments during the unit progression. A suggestion would be to be intentional with designating formative assessments. They could act as clear mile markers for teachers to assess students to know if continuing forward with the plan is appropriate. The final performance task assessment has a detailed rubric that is located on page three of the resource. There is also places where vocabulary and science terms are part of the daily activity, homework, or woven within a lesson.

  • Quality of Technological Interactivity: - none -