Uncertainty and Error

Question 1

An estimate of the range within which the error lies either side of the
actual value.

Answer 1

UNCERTAINTY

Question 2

Expresses the margin of
uncertainty associated with a
measurement

Answer 2

Absolute uncertainty

Question 2

Compares the size of the
absolute uncertainty with the
size of its associated
measurement.

Answer 2

Relative uncertainty

Question 3

=ABSOLUTE UNCERTAINTY/MAGNITUDE OF MEASUREMENT

Answer 3

Relative Uncertainty

Question 4

100xRelative Uncertainty

Answer 4

Percent Relative Uncertainty

Question 5

the uncertainty in the
answer is obtained from
the absolute
uncertainties of the
individual terms as
follows:

Answer 5

Addition and
Subtraction

Question 6

e4=SRe1^2+e2^2+e3^2

Answer 6

Addition and Subtraction

Question 6

• 1. convert all uncertainties
     into percent relative
     uncertainties
• 2. calculate the error of the
     product or quotient as
     follows:

Answer 6

Multiplication
and Division

Question 7

▪ the difference between a single
observed value and the sample
mean, (𝑥 − 𝑥𝑖 ) and has both sign and
units
▪ can provide a useful comparison
between successive individual values
within a set of measurements,
particularly when presented visually
in the form of a residual plot.

Answer 7

RESIDUALS

Question 8

• refers to the consistency
  between individual values
  amongst a set of replicate
  measurements performed by
  the same person, at the same
  time on the same sample,
  using the same method

Answer 8

REPEATABILITY

Question 9

■ refers to the consistency of a
method as used by different
analysts, laboratories, and/or

Answer 9

REPRODUCIBILITY

Question 10

■ describes the precision of
within-run replicates.

Answer 10

REPEATABILITY

Question 11

The reproducibility of a
method is normally expected
to be poorer (i.e. with larger
random errors) than its
repeatability.

Answer 11

REPRODUCIBILITY

Question 12

■ describes the precision of
between-run replicates.

Answer 12

REPRODUCIBILITY