Key Definitions 

Introduce two measurement concepts and write the definitions on the board. 

• Accuracy: how close the results are to the truth (whether the measurements are correct) 
• Precision: how consistent the results are to one another (if measured more than once) ● If needed, use this video 

Sorting Objects 

• Students will sort objects into one of three categories: (create a large three column t-chart on the board)
  1. Yes, it can be measured accurately and precisely 
  2. Kind of, it can be measured but not perfectly accurately or precisely 
  3. No, it cannot be measured with any accuracy or precision 
• The activity begins with the nomination of a possible measurement for discussion. When the “thing” is nominated, write the word/phrase in a “nomination box” on the board. 
• The class will inquire with open discussion about which category this thing fits into.
  • Recommendation: When the conversation comes to a close or ideas are being repeated without new contributions, conduct a class vote about where to place this “thing.” Erase the word from the nomination box and move it to the column with the most votes. 
  • Recommendation: Encourage students to reference the “accuracy” and “precision” definitions and to specify different ways they think this thing can be measured.
• The discussion about each example should touch on these questions: (as the facilitator, guide them towards these ideas)
  • How accurate could we measure this example? 
  • How precise would our measurements of this example be? 
  • What method/ technique would we use to measure this example? 
  • Is there more than one method/ technique that would work? What are the benefits or drawbacks of each method? 
• Key Teaching Move: For the first three “things”, it might be helpful for the teacher to begin the nomination as examples.
  • Recommendations (pick your favorites or come up with your own!):
    1. the height of a baby giraffe 
    2. the amount of water in the ocean 
    3. how fast a student can read 
    4. how well a student understands a passage they just read 
    5. how fair someone is on the playground 
    6. how many days a tree has been alive 
    7. the number of words in a chapter book 
    8. how much your dog loves you 
    9. the temperature on Mars 
  • After three nominations by the teacher, discuss: 
    • What makes a good nomination? 
    • Students should identify that a good nomination will be one that chooses an object and something that you might be interested in measuring about that object. 

• Now the students will get to make nominations for discussion! There are many ways you can conduct this part:
  1. Have students raise their hands and nominate out loud. If the nomination isn’t a “good” one, probe the student about their object for what they might be interested in measuring about that object. 
  2. Have the students each write one measurement nomination on an index card. 
     Collect all the cards, put them into a bucket, and pull them out at ransom. 
  3. Have students work in small groups (2-4) to come up with 3 nominations they would like to discuss with the whole class. Call on groups one at a time for a nomination. 
     • Note: You can get creative with how you facilitate student nominations. You know your students the best. Just keep in mind that it is important that every student feels like there is an opportunity to share their ideas. 

Creating Criteria

What do all the examples in each category have in common? 

• Once you feel like there are enough “things” on the board in each category, facilitate a discussion about each category:
  1. Yes, it can be measured accurately and precisely
     • What do all of these examples have in common? 
     • What makes it so that these things can be measured accurately and precisely? 
  2. Kind of, it can be measured but not perfectly accurately or precisely
     • What do all of these examples have in common?
     • What makes it hard for these things to be measured accurately and precisely? 
  3. No, it cannot be measured with any accuracy or precision
     • What do all of these examples have in common?
     • What makes it impossible for these things to be measured accurately and precisely? 

Meta-Reflection

How did this activity go? 

Ask students: 

• How can we measure how successful this philosophy session was? 
  • Note: Guide students to consider (1) what would make this activity successful and (2) how we could tell (measure) whether it was successful
    • Conduct measurement determined as a class 
  • Note: This could be a thumb gauge of how everyone felt, a poll 1-10 where the teacher averages individual responses, student free write reflections, and many others. 

Or, instead of the whole activity or just the concluding meta-reflection, you can conduct a Community of Inquiry using these philosophy questions: 

• Why do we measure things? 
• Is it necessary to measure all things? Why or why not? 
• What makes something easier or harder to measure? 
• What would it be like if we could not measure different things accurately or precisely? 
• What would it be like if we could measure everything perfectly accurately and precisely? 
• Is there anything we should not measure? Why?