Critical Response

Question 1

Explain how systematic error could be identified.

Answer 1

• By repeating the experiment with new equipment or freshly calibrated apparatus (such as…?).
• If the new results differ consistently from the original results, this indicates systematic error is present.

Question 2

Explain the difference between accuracy and precision.

Answer 2

• Accuracy – how close measured values are to the ‘true value’
• Precision – how close measured values (of multiple trials) are to each other (e.g. the reproducibility of measurements under the same conditions)

Question 3

Explain the importance of increasing the sample size.

Answer 3

• To reduce the effect of random error, but enabling more reliable averages to be calculated.

Question 4

Explain why it is important to keep all factors constant apart from the independent variable.

Answer 4

• So that the results of the experiment / dependent variable is solely due to the independent variable.
• Therefore a direct cause-and-effect relationship between the two variables can be determined.
• This will enable a valid conclusion to be drawn.