Universal Constants: A New Foundation of Measurement    >   Measure - Pursue Accuracy

Journal Thread #2 / Prompt 1 - On the Road Again

Watch the NIST Role Models explain consensus standards, then go back in time to consider the importance of agreeing on standards.

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Title of Activity:

Journal Thread #2 / Prompt 1 - On the Road Again

Curriculum Collection:

NIST: Universal Constants - Lesson 1

Brief Description:

Students watch the NIST Role Models explain why consensus standards are important. Then, using a historical analogy, students reflect on the use of agreed-upon artifacts for measurement.

Target Grade Level:

Grades 8-12

Discipline or Course:

Physical Science

Time Frame:

One 45-minute session 

Suggested Grouping:  


Key Vocabulary:

  • Artifact
  • Standard

Teacher Prep:

This journal prompt involves a basic discussion of trade using currency vs. trade by barter.

If coins are used for trade, there is the presumption that somewhere there are smiths making the coins, and that the forging of the coins would involve an artifact or standard coin. Savvy traders would have some sense of the size and mass. But coins also could have a “face value” rather than being precisely valued by their mass.

By contrast, using a commodity like silk would involve a measuring instrument (e.g. a cubit of silk). The measuring instruments might not be consistent across different places. Over the vast miles of the Silk Road, the standard would certainly degrade like a long game of “telephone” since there would be no way for a trader in the Middle East to directly and immediately compare their ruler to the standard used in India.

The rubric can be modified for student, whole class, or teacher use.

Possible Rubric





Constructing Explanations

No explanation of how an artifact was involved

Reference to an artifact but no explanation of how it could be used

Clear explanation of how an artifact could be used

Explanation of potential artifacts in the trading process

No evidence that the student understands the process or use of an artifact

Partial evidence that the student understands the process or use of an artifact

Solid evidence that the student understands the process or use of an artifact

Identification of arguments based on evidence

No discussion of difficulties or sources of error

Reference to difficulties or sources of error without explanation

Clear explanation of how the method might involve sources of error


Watch the NIST Role Models explain consensus standards.

NIST Role Models - Consensus Standards

Think about what the scientists say about the importance of agreeing on standards. Now, go back in time to consider how that occurred in the past.

Over 10,000 years ago, a linked set of roads and trails helped merchants bring goods from China to the Middle East and Europe. The Silk Road was 7,000 miles long, and it brought together a wide range of cultures, languages, and traditions.

The Silk Road was not just a way to make money. It was also an important pathway to exchanging technologies. Knowledge of the magnetic compass, the printing press, the chemistry of gunpowder, ceramics, and even wine-making flowed along with people and goods.

Most of the trades on the Silk Road were made with coins. All gold coins of a certain size were presumed to have the same weight. Some traders bartered silk or spices.

  • What was the advantage of using coins over bartering goods?
  • What were the disadvantages?

Imagine you are a trader at a Silk Road weigh station 3,000 years ago. Argue that your standard of exchange is accurate to a skeptical potential buyer. What artifacts would be used to make your case?

Remember to argue from the evidence!