3. Design A1
Must include : -
A research question of the form ‘ what is the
effect of changing x on the quantity y ‘
Independent
Dependent
Control
Notes : All numbers must be associated with units
and uncertainty. Significant figures must be
consistent. Your choice of variables must be
scientifically robust.
4. Design A2
• Method usually of bullet point format.
• Must clearly state how the variables identified in
1 are to be controlled and measured.
• Write as though you were asking a fellow scientist
to repeat the procedure.
• Make your control variables realistic.
• Have only one dependent and one independent
variable.
• Include ranges and uncertainties of all glassware,
and apparatus.
5. Design A3
• You should always target 5 data points
repeated in triplicate.
• Your method must have accounted for limiting
reagent issues which may preclude you
recording relevant data.
6. • Random errors
These arise from the imprecision of measurements and can lead to
readings being above or below the “true” value. Random errors can be
reduced with the use of more precise measuring equipment or its effect
minimized through repeat measurements so that the random errors
cancel out.
Systematic errors
These arise from a problem in the experimental set-up that results in the
measured values always deviating from the “true” value in the same
direction, that is, always higher or always lower. Examples of causes of
systematic error are miscalibration of a measuring device or poor
insulation in calorimetry experiments.
Accuracy
This is how close a measured value is to the correct (literature) value.
Precision
This indicates how many significant figures there are in a measurement.
Human Errors
These are due to the incompetence of the operator conducting the
experiment and should not be included in your report
