Comparing Data Collection Methods

The experiment: Three student groups each measured the temperature of the same cup of water. A calibrated reference thermometer was used afterward to confirm the true temperature.
True value: 22°C

Method A Digital thermometer

Trials:3

Trial	Temp (°C)
1	21
2	22
3	23
Average	22.0

Method B Hand estimate

Trials:1

Result:

“about 30°C”

Average:N/A — single estimate

Method C Old thermometer

Trials:3

Trial	Temp (°C)
1	27
2	28
3	28
Average	27.7

Q1Which method produced the most accurate result?

Method A — digital thermometer, average 22.0°C Method B — hand estimate, "about 30°C" Method C — old thermometer, average 27.7°C

Q2Which method is most reliable (would give consistent results if repeated)?

Method A — three trials ranging from 21–23°C (2°C spread) Method B — one hand estimate, no repeat trials Method C — three trials ranging from 27–28°C (1°C spread)

Q3Which method has the greatest measurement error compared to the true value?

Method A — average 22.0°C vs true value 22°C Method B — estimate of ~30°C vs true value 22°C Method C — average 27.7°C vs true value 22°C

Evaluating Data Collection Methods