Dart Drop Accuracy, Precision, and Uncertainty

Students drop different darts onto a target from varying heights and by different droppers, then analyze how accuracy (closeness to the center), precision (clustering), and uncertainty (spread/standard deviation) change with those variables.

1. Tape a printed target to a flat board (wood or particle board) and place it on the floor.
2. Select three noticeably different darts; assign one primary dropper and two additional droppers.
3. Measure and mark drop heights (e.g., 2 ft, 4 ft, 6 ft) using a tape measure.
4. For each trial, drop the specified dart from the specified height the required number of times (e.g., 8 drops), keeping the dart vertical and releasing without push.
5. After each drop, mark the hole location on the target (or photograph) so hits from each trial are distinguishable; use a fresh target per trial.
6. Record polar coordinates for each hit: radius (distance from center) and angle; organize data in a table for every trial.
7. Compute for each trial: average radius (accuracy proxy), standard deviation of radius (uncertainty), and plot average radius with ±1σ error bars.
8. Compare conditions by plotting:
   1. Average radius vs drop height (constant dart and dropper).
   2. Average radius vs number of drops (constant dart, height, dropper).
   3. Average radius vs dart type (constant height and dropper).
   4. Average radius vs dropper (constant dart and height).
9. Summarize findings: identify which variables most affected accuracy and precision; note any outliers and likely causes.

📄 Simple and Fun Experiment Demonstrating Accuracy, Precision, and Uncertainty - Charles Baukal: file:///C:/Users/ameier/Downloads/simple-and-fun-experiment-demonstrating-accuracy-precision-and-uncertainty%20(1).pdf

• Add a short “practice” set before official trials to reduce learning effects, then compare with first official trial.
• Increase the maximum number of drops (e.g., 20) to test how sample size changes standard deviation.
• Use heavier vs lighter darts to test mass effects; repeat under a fan to probe air-current sensitivity.
• Replace the circular target with concentric scoring rings to enable a scoring-based accuracy metric.
• Run outdoors vs indoors to compare environmental effects.

• Darts are sharp - no horseplay, keep a clear zone around the drop area.
• Wear closed-toe shoes; never reach over the target while someone is dropping.
• Lift darts straight up from the board to avoid splinters and tip damage.
• Use a sturdy backer (particle board preferred) to protect floors and prevent bounce.
• Step stools or ladders (if used for higher drops) require adult supervision and three-point contact.

* What is the difference between accuracy and precision? (Accuracy = closeness to true value/center; precision = tightness of clustering regardless of center.)

• Did increasing the number of drops change your uncertainty? (Often the standard deviation estimate stabilizes with more data; report your trend.)
• How did drop height affect accuracy and precision, and why might that be? (Greater height can increase scatter due to small alignment errors and air currents.)
• Did dart type (mass/shape) matter? (Heavier darts may be less affected by air currents; compare your averages and spreads.)
• Which contributed more to variability—equipment (dart/height) or human factors (dropper)? (Support with your error-bar comparisons.)
• How would you redesign the experiment to reduce confounding variables? (Standardized practice, identical dart sets, randomized trial order, blinding of droppers.)