AS Physics Practical...

Initially, students can be asked to estimate the actual error in the measurements they make and to convert this into a percentage error. In this way they can be asked, as a matter of routine, to identify the largest sources of error in the experiment.
They should also be taught the difference between random and systematic errors and encouraged to check for systematic errors in their measurements.
From this starting point, students can begin to use checklists to help them to think about the limitations in an experiment.

The checklist could include the following questions.

• Apart from the variables being measured, was there any other factor that might have
affected the results?

• Which measurements were difficult to make?

• What were the largest sources of error?

• Were there any systematic errors?

• Was enough data collected?

• Was the range and distribution of the data points appropriate?

• Was a graph of the data plotted?






or rather
Points for evaluation:

* 2 points of data are not enough
* do repeats
* put white card behind experiment
* dye any liquid
* close windows
* Use a fiducial mark
* Minimize parallax
* Use data logging N.B. Must say sensors (e.g. Light gate)
* Plot a graph


Hope this may help you score that 8 marks.