1. Slideshow P4: Drawing a line graph

2. Features of a good line graph A 'line of best fit' can sometimes be drawn to show the pattern of the plotted points. This may not be a straight line. This axis should always show the variable which has been measured, and results collected for. Both axes should have a label and a unit. They should have a regularly spaced number scale and usually, but not always, start from 0. Points should be plotted accurately by drawing a small cross with a sharp pencil. The centre of the cross must be exactly at the point being plotted. This axis should always show the variable that has been changed.

3. Analysing a line graph The average of several results is plotted. Unusual results have been discounted. There is a clear best-fit line through the points. The line shows that if the force is doubled, the distance doubles. If the force is three times, the distance is three times. Distance data for other force values would be needed to confirm this relationship.