Check understanding

• Describe a dot plot of 25 pupils' reaction times by its centre (a typical value), its spread (where most values lie and how far they extend) and its shape — naming any cluster, gap, symmetry or skew and unusual value — and link each feature to the context (e.g. a gap between two groups of times might reflect pupils who had practised and pupils who had not)
• Compare two distributions with the same mean — e.g. two classes both averaging 60% on a test, one with scores clustered between 52% and 68%, the other spread from 20% to 95% in two separate clusters — and explain what the shared mean hides and why the difference matters in context
• Use the context to judge whether an unusual value is more likely a recording error or a genuine extreme (e.g. a reaction time of 4.2 s among times near 0.3 s), and identify claims the display alone cannot support, such as the reason for a skew or that the same pattern would hold for a different group

“If your child sees a dot plot of how long children in their class took to run 100 m, could they describe where most times bunch up, how spread out they are and whether there are any odd ones out — and suggest a sensible reason for what they see?”