Plotting is where measured data becomes a picture, so accuracy here decides how reliable everything after it will be. Each point should be marked with a small, sharp cross or a fine dot in a circle, not a thick blob that hides its exact position.
Aim to place every point to within half a small square of its true value on both axes. Read the scale carefully, count the squares, and mark precisely rather than estimating roughly.
After plotting, look at the overall pattern. Genuine data usually forms a clear trend, and a point far off that trend may be a plotting slip worth rechecking before you draw the line.
Careful plotting protects every later step. A best-fit line and a gradient can only be as accurate as the points they are built on, so time spent plotting precisely is time well spent.
What examiners award
Marks are awarded for points plotted accurately to within half a small square, marked with small sharp crosses or fine dots.
Common mark losses
In short
Plot each point with a small, sharp cross or dot, positioned to within half a small square. Accurate points are the foundation of a trustworthy line.
A routine that works
Practise the mechanics until they are automatic: label both axes with units, choose a scale that fills more than half the grid, plot points with a sharp pencil, draw a single best-fit line, and take the gradient from a large triangle with its coordinates and unit shown. One clean example beats re-reading the theory.
Source: DSKP KSSM Physics Form 4 and 5 (Versi English) (Bahagian Pembangunan Kurikulum (BPK), KPM)