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Lesson 15: Ready, Sense, Go!

Lesson 15: Ready, Sense, Go!


Students will learn what sensors are and how they are used to collect data.


  1. Video: Play Like Nadal With a Smart Tennis Racket

  2. Computers (see Step 5)

  3. Poster paper

  4. Flags in 3 different colors

    Advanced preparation required (see Step 10 below)


sensor trigger algorithm

Essential Concepts:

Essential Concepts:

Sensors are another data collection method. Unlike what we have seen so far, sensors do not involve humans (much). They collect data according to an algorithm.


  1. Entrance Ticket: What are some of the data collection methods we have learned about so far in this unit? We have learned about experiments, observational studies, surveys, and getting data from a URL (in Lab 3B).

  2. Inform students that, in this lesson, they will be introduced to another data collection method known as sensors.

  3. With a partner, ask students to discuss what they think a sensor is. Ask each pair to write down their ideas.

  4. Show the Play Like Nadal With a Smart Tennis Racket video found at: As students watch the video, they should think about other sensors they may have come across, particularly ones used with smartphones. After watching the video, ask students to add to their definition of a sensor.

  5. Now, inform students that they will work in teams to compile a list of data-collecting sensors. They may use computers to conduct online research for this part of the lesson. Challenge each team to generate the longest list in the class.

  6. After students have had time to research and create their lists, ask students in each team to number off one through four (or five, depending on team sizes).

  7. Share out in rounds. First, ask students in each team whose number is one to share one sensor from their list. On the poster paper, create a class list of sensors as shared by the students. Repeat with the rest of the numbers.

  8. Score keeping: Each person gets five seconds to respond. You may hold up your hand with the palm facing the students and count down. The rules for teams are as follows:

    1. add a sensor to the list, get 1 point

    2. repeat an answer, lose 1 point

    3. do not answer in five seconds, lose a turn

    4. do not have an answer to contribute, may pass

    Note: You may reward the winning team with extra credit points, if desired.

  9. Next, students will engage in an activity to see sensors in action.

  10. Create 3 groups of students:

    1. Group 1 – Triggers (3 students)

      Provide each Trigger a different colored flag (for example: Pink, Purple, Green). The teacher will call out a color, at random, and the Trigger assigned to that color will raise his or her flag. Each flag corresponds to a research question of interest.

      Pink – Who is in our class?

      Purple – What is on our classroom walls?

      Green – What do we like to do after school?

    2. Group 2 – Sensors (2 students)

      Each Sensor should be assigned to one Trigger, or colored flag (Pink = Sensor A, Purple = Sensor B, Green = no sensor assigned to it). When the Sensors see their assigned Trigger, they send a signal to the Collector (see below) telling him or her to collect data from another student in the class. The Sensors are basically gobetweens for the Triggers and the Collector.

    3. Group 3 – Collector (1 student)

      One student is the Collector of all the data. The Collector is in charge of asking survey questions related to the research question of the original Trigger. Survey questions are provided here:

      Survey questions related to the Pink trigger:

          (1) How did you get to school today (bus, car, walking, etc.)?

          (2) What size shoe do you wear?

          (3) What is your favorite pizza topping?

      Survey questions related to the Purple trigger:

          (1) What is your favorite wall decoration?

          (2) What type of poster is it (motivational, reference, class work, etc.)?

          (3) What color is most prevalent in the poster?

      Survey questions related to the Green trigger:

          (1) Do you have a sports team practice or club meeting today?

          (2) Are you hanging out with friends today after school?

          (3) Will you be working today after school?

      Each time a sensor is active, the Collector must ask a new student in the class the appropriate survey questions.

  11. Explain the activity to your students. Then, call out a flag color at random. Repeat several times. Make sure you call out the flag that has no assignment at least once so that students see that no action took place. Reflect on the activity with the following discussion questions:

    1. What data were missed? Why? Data about what our class likes to do after school. They were missed because there was no Sensor connected to the Green trigger, so the Collector never knew to collect this type of data.

    2. Grocery stores keep track of customer data when purchases are made with a loyalty card. What is the trigger in this case? What data are being collected? The trigger is checking out at a grocery store. There are lots of data that are collected, including: items bought, cost of items, number of items on sale, etc.

  12. After they engage in the sensor activity, ask students to revisit their definition of a sensor (see Step 3). Have them revise their definition based on the following concepts:

    1. A sensor is a converter that measures a physical quantity and converts it into a signal, which can be read by an observer or by an instrument.

    2. A sensor collects data continuously, or whenever a trigger is activated. A trigger is a something that responds to an event so that an action can occur.

    3. Sensors collect data according to an algorithm. An algorithm is a process or set of rules that are followed (just like the rules followed during the activity).

    4. Sensors may also collect data automatically, without anyone’s knowledge or input. Examples include GPS location, time, and date.

Class Scribes:

One team of students will give a brief talk to discuss what they think the 3 most important topics of the day were.


Now that students learned what sensors are, ask them what data they would they like to see collected on a sensor that they couldn't collect in an experiment or survey. They must explain why it is difficult to collect that data in an experiment or survey, and how a sensor would make it easier to collect that data.