Subject specific vocabulary

Question 1

Accuracy.

Answer 1

• Considered accurate if judged to be close to true value.

Question 2

Calibration.

Answer 2

• Marking a scale on a measuring instrument.
• Involves establishing relationship between indicators of a measuring instrument + standard/reference quantity values.

Question 3

Data.

Answer 3

• Information (qualitative or quantitative) that has been collected.

Question 4

Measurement error.

Answer 4

• Difference between measured value and true value.

Question 5

Anomolies.

Answer 5

• Values in a set of results which are judged to not be part of the variation caused by random uncertainty.

Question 6

Random error.

Answer 6

• Reading spread about true value, results vary in unpredictable way from one measurement to ext.

Question 7

How can we reduce the effect of random error?

Answer 7

• Making more measurements + calculating new mean.

Question 8

Systematic error.

Answer 8

• Readings differ from true value by consistent amount.

Question 9

What causes systematic errors?

Answer 9

• Environment, methods of observation or instruments used.

Question 10

How can systematic errors be fixed?

Answer 10

• Data collection should be repeated using different technique or different equipment + compare results.

Question 11

Zero error.

Answer 11

• Indication that a measuring system gives a false reading when true value should be zero.
• May result in systematic uncertainty.

Question 12

Evidence.

Answer 12

• Data which has been shown to be valid.

Question 13

Fair test.

Answer 13

• One in which only independent variable has been allowed to affect the independent variable.

Question 14

Interval.

Answer 14

• Quantity between readings.

Question 15

Precision.

Answer 15

• Precise measurements are ones in which there is very little spread around the mean value.
• Depends only on extent of random errors.

Question 16

Predicition.

Answer 16

• Statement suggesting what will happen in future, based on observation, experience or a hypothesis.

Question 17

Range.

Answer 17

• Max. + min. values of independent + dependent variables.
• Important in ensuring that any pattern is detected.

Question 18

Repeatable.

Answer 18

• Only repeatable if the original experimenter repeats same investigation same method + equipment + obtains same results.

Question 19

Reproducible.

Answer 19

• Only reproducible if investigation is repeated by another person or using different equipment or techniques + same results are obtained.

Question 20

Resolution.

Answer 20

• Smallest change in quantity being measured of a measuring instrument that gives perceptible change in reading.

Question 21

Uncertainty.

Answer 21

• Interval in which true value can be expected to lie with a given level of confidence/probability.

Question 22

Validity.

Answer 22

• Suitability of investigative procedure to answer question being asked

Question 23

Valid conclusions.

Answer 23

• Conclusion supported by valid data, obtained from an appropriate experimental design + based on sound reasoning.

Question 24

Variables.

Answer 24

• Physical, chemical or biological quantities or characteristics.

Question 25

Categoric variables.

Answer 25

• Variables that have values that are labels.
• e.g. names of plants or types of materials.

Question 26

Continuous variables.

Answer 26

• Can have values that can be given a magnitude either by counting or by measurement.