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Define "accuracy". Explain it in simple terms.
How close a set of measured values are to the "true value".
Define "precision". Explain it in simple terms.
How close a set of measured values are to the MEAN.
What is a measurement error? Explain it in simple terms.
a mistake when taking a measurement.
What is a random error? What are two characteristics of it? 1. It affects ___ measurement (can cause an ___________ result) 2. the result is __________
Examples: Parallax error / random fluctuations
What is a systematic error? What are two characteristics of it? 1. It affects ___ measurement(s) 2. the result is __________
Examples: Zero error / incorrect technique
Decide if the source is from a random or systematic error: relying on your own reaction time when starting and stopping a stopwatch to take measurements of time.
random
Decide if the source is from a random or systematic error: Measuring distance using a metre ruler which has been worn down by years of use so that the zero mark is missing.
systematic
Decide if the source is from a random or systematic error: taking temperature readings with a thermometer while the mercury level is still rising.
random
Which type of error can be reduced by calculating a mean?
random errors
Which type of error affects a single measurement?
random
Which type of error affects all measurements?
systematic
Which type of errors are predictable?
systematic errors
Which type of errors are consistent? (What does consistent mean?)
systematic errors / happens a lot over time, you can count on it to happen, you can expect it to happen
Calculate the mean of the following distance measurements: 12.8 cm, 12.7 cm, 13.0 cm, 10.5 cm, 12.9 cm
12.8 cm + 12.7 cm + 13.0 cm + 12.9 cm / 4 = 12.85 (Mean) *ignore 10.5*
Why should measurement be repeated? (two reasons)
to spot anomalies (random errors) / to calculate a mean (which reduces random errors)
