|
2
marks
|
a.
possible sources of errors
b.
observations about discrepancies or anomalies in the experimental
data
c.
variation in repeat readings or repeated observations indicating an
uncertainty in the data
d.
comment on discrepancies between expected results or outcomes and
the experimental evidence
|
|
a. sources of error which need not include the most significant
c.
comment on the
spread of repeat readings, if any
|
|
4
marks
|
a.
identification of the most significant measurement(s) (e.g. a value
to be squared in processing or the measurement of a very small quantity)
b.
estimate of error or uncertainty in till measurements based on
experimental data or evidence
c.
comment on the reliability of the techniques used
d.
comment on the reliability of the conclusions drawn
|
|
d.
for example, closeness of plotted points to the line of best fit.
|
|
6
marks
|
a.
identification of possible sources of systematic errors in addition
to the identified random errors
b.
critical analysis of techniques used and associated errors and
suggestions for improvement in experimental plan or techniques(s) to
minimise errors
c.
critical assessment of reliability of conclusions and / or final
quantitative “answer” in light of error-estimates and critical
analysis of experimental technique(s)
d.
proposals
for improvements, or further work. To provide additional or more reliable
evidence for the conclusion or to extend the investigation in a different
or potentially more successful direction
|
|
a.
for example, zero error on a measuring instrument
b.
comment as to why any proposed
improvements should improve the reliability
c. for example, why a straight
line graph fails to pass through the origin as predicted
|