How Accurate and Precise Are Dart Players?

Talk It Over

Are some family members or friends better at darts than you are? What makes a good dart player? How can we measure the difference among people's performance at darts?

Get

• Dart board
• 3 darts
• Camera
• Ruler
• 3 or more willing dart players

Go

•  The distance between the darts (comparing two at a time)

•  The distance of each dart from the center of the bull's-eye.

1. Ask a dart player to throw 3 darts into the board. The goal is to hit the bull's-eye in the center. Let a player who misses the board try again until 3 darts are stuck in the board.
2. Take a picture of this player's darts.
3. With the ruler, measure
4. Repeat steps 1–3 with each dart player you test.

In everyday talk, we use the words precise and accurate as if they mean the same thing. They don't—at least not in the science of measurement. Precision is how uniform or consistent measurements are. For the dart player, it is how close together the darts are. In this experiment, the average distance between darts is a measure of precision. Accuracy is different. It is the quality of the result, or how close it comes to the true value. In this case, the true value is the goal of the game, hitting the bull'seye.The average distance to the bull's-eye is a measurement of accuracy.

The following result is precise, but not very accurate:

The following result is accurate, but not very precise:

The following result is both precise and accurate:

So, to analyze your data, calculate for each player

• Precision: the average distance between the darts:
• Accuracy: the average distance between the bull's-eye and the darts:

Stay Safe

Stay out of the way when darts are being thrown, and do not horse around with darts. Even plastictipped ones can cause injury.

Go Easy

Get an adult to help you with setups, measurements, photography, and calculations.

Go Far

Expand your project by giving your dart players practice time. Limit them to 10 practice throws or 5 minutes of practice—whatever you like, as long as each player gets the same treatment. Then measure and calculate distances as you did in "Go." Compare it to each player's pre-practice performance. Try to answer the following question: How does practice affect the precision and accuracy of dart players?

Show Your Results

Record your measurements and calculations in data tables like these:

For "Go Easy" and "Go," make bar graphs that compare the average precision and the average accuracy of the players. Display your pictures to show how accuracy and precision varied.

For "Go Far," make bar graphs that show the change in accuracy and precision after practice. The average difference pre- and post-practice will tell you whether practice improved performance. Your graphs will show how individuals varied in the effect of practice.

Tips and Tricks

• Measure in millimeters from tip to tip for the distance between darts.
• Measure in millimeters from the exact center of the bull's-eye to the dart tip.

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