Scientific vocabulary

Question 1

Accuracy

Answer 1

measurement result is considered accurate if it is judged to be close to the true value.

Question 2

Calibration marking

Answer 2

a scale on a measuring instrument. This involves establishing the relationship between indications of a measuring instrument and standard or reference quantity values, which must be applied. For example, placing a thermometer in melting ice to see whether it reads zero, in order to check if it has been calibrated correctly.

Question 3

data information

Answer 3

either qualitative or quantitative, that has been collected.

Question 4

error

Answer 4

see also uncertianty

Question 5

measurement error

Answer 5

The difference between a measured value and the true value.

Question 6

Anomalies

Answer 6

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

Question 7

uncertainty

Answer 7

The interval within which the true value can be expected to lie, with a given level of confidence or probability, eg ‘the temperature is 20 °C ± 2 °C, at a level of confidence of 95%’.

Question 8

Resolution

Answer 8

This is the smallest change in the quantity being measured (input) of a measuring instrument that gives a perceptible change in the reading.

Question 9

repeatability

Answer 9

A measurement is repeatable if the original experimenter repeats the investigation using same method and equipment and obtains the same results. Previously known as reliable.

Question 10

reproducible

Answer 10

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. Previously known as reliable.

Question 11

precision

Answer 11

Precise measurements are ones in which there is very little spread about the mean value. Precision depends only on the extent of random errors – it gives no indication of how close results are to the true value.

Question 12

Validaty

Answer 12

Suitability of the investigative procedure to answer the question being asked. For example, an investigation to find out if the rate of a chemical reaction depended upon the concentration of one of the reactants would not be a valid procedure if the temperature of the reactants was not controlled.