Glossary Of Practicals Terms

Question 1

Accuracy

Answer 1

It is judged to be close to the true value

Question 2

Calibration

Answer 2

Marking a scale on a measuring instrument. Involves establishing the relationship between indications of a measuring instrument and standard or reference quantity values, which must be applied.

Question 3

Data

Answer 3

Information, either qualitative or quantitative, that has been collected

Question 4

Errors

Answer 4

Uncertainties

Question 5

Measurement error

Answer 5

Difference between a measured value and the true value

Question 6

Anomalies

Answer 6

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

Question 7

Random error

Answer 7

These cause readings to be spread about the true value, due to results varying in an unpredictable way from one measurement to the next

Question 8

Systematic error

Answer 8

Cause readings to differ from the true value by a consistent amount each time a measurement is made. From environment, methods of observation or instruments used

Question 9

Zero error

Answer 9

Any indication that a measuring system gives a false reading when the true value of a measured quantity is zero

Question 10

Evidence

Answer 10

Data that has shown to be valid

Question 11

Fair test

Answer 11

one in which only the independent variable has been allowed to affect the dependent variable

Question 12

Hypothesis

Answer 12

A proposal intended to explain certain facts or observations

Question 13

Interval

Answer 13

The quantity between readings

Question 14

Precision

Answer 14

Ones in which there is very little spread about the mean value.

Question 15

Prediction

Answer 15

A statement suggesting what will happen in the future, based on observation, experience or a hypothesis

Question 16

Range

Answer 16

The maximum and minimum values of the independent and dependent values.

Question 17

Repeatable

Answer 17

A measurement is repeatable if the original experimenter repeats the experiment using the same method and equipment and obtains the same results

Question 18

Reproducible

Answer 18

A measurement is reproducible if the investigation is repeated by another person, or by using different equipment or techniques, and the same results are obtained.

Question 19

Resolution

Answer 19

The smallest change in the quantity being measured of a measuring instrument that gives a periceptible change in the reading

Question 20

Sketch graph

Answer 20

A line graph, not necessarily on a grid, that shows the general shape of the relationship between two variables. It will not have any points plotted and although the axis should be labelled they may not be scaled

Question 21

True value

Answer 21

The value that would be obtained in an ideal measurement

Question 22

Uncertainty

Answer 22

The interval within which the true value can be expected to lie, with a given level of confidence or probability

Question 23

Validity

Answer 23

Suitability of the investigative procedure to answer the question being asked

Question 24

Valid conclusion

Answer 24

A conclusion supported by valid data, obtained from an appropriate experimental design and based on sound reasoning

Question 25

Variables

Answer 25

Physical, chemical or biological quantities or characteristics

Question 26

Categoric variables

Answer 26

Have values that are labels

Question 27

Continuous variables

Answer 27

Can have variables that can be given a magnitude either by counting or by measurement

Question 28

Control variables

Answer 28

Is one which may, in addition to the independent variable, affect the outcome of the investigation and therefor has to be kept constant or at least monitored

Question 29

Dependent variables

Answer 29

The variable of which the value is measured for each and every change in the independent variable

Question 30

Independent variables

Answer 30

Is the variable for which values are changed or selected by the investigator

Question 31

Nominal variables

Answer 31

A type of categoric variable where there is no ordering of categories