Draft: Evaluating Precision

Use the example of a series of repeated length measurements to explain the meaning of precision.

• Precision refers to how close the repeated measurements are to each other.

• Precision refers to how close the measurements are to the true value.

• Precision is the ability to measure accurately without error.

• Precision is the range of values obtained from repeated measurements.

What information would you need to determine the accuracy of a measurement?

• The precision of the measurement tool

• The unit of measurement used

• The environmental conditions during measurement

• The calibration status of the measurement tool

Tags

NGSS.MS-PS1-2

Drawing Conclusions: In this investigation, you will compare measurements that you make to measurements that your classmates make. Will you do this to determine the accuracy or the precision of your measurements?

• Accuracy

• Precision

Designing Experiments: Identify the manipulated, responding, and controlled variables in this investigation. c. Controlled variables

• Temperature, light, and time

• Amount of water, type of soil, and plant species

• Type of fertilizer, amount of sunlight, and watering frequency

• All of the above

What materials are needed for the experiment?

• Beakers, test tubes, and chemicals

• Books and pens

• Computers and software

• Sports equipment

After all three teams have finished measuring, what should be done next?

• Analyze the data collected by each team

• Start a new measurement task

• Discuss the results with the teams

• Submit the measurements for review

Tags

NGSS.MS-ETS1-3

NGSS.MS-PS3-4

1. Calculating: What is the average of the three length measurements you compared by adding them together and dividing the result by 3?

• The sum of the measurements divided by 2

• The sum of the measurements divided by 3

• The sum of the measurements divided by 4

• The sum of the measurements divided by 5

2. Making Generalizations: Would it be correct to use the range of values you calculated in Question 1 to describe the precision of the measurements? The accuracy of the measurements? Explain your answer.

• Yes, it describes both precision and accuracy.

• No, it only describes precision.

• No, it only describes accuracy.

• Yes, it describes neither precision nor accuracy.

Tags

NGSS.HS-PS1-3

What could be a reason for differences among the teams’ measurements?

• Different measurement tools used

• Identical measurement techniques

• Consistent environmental conditions

• Uniform team experience levels

Which of the following steps is essential in designing an experiment to compare the precision of two or more measuring instruments?

• Select instruments with the same brand.

• Ensure the instruments are calibrated.

• Use instruments only for a single measurement.

• Choose instruments with different measurement ranges.