The purpose of creating a graphic and placing it on a school website is to allow stakeholders (parents, students, employees) to determine some meaning and to come to some conclusions - normally something about the progress of the school I would imagine.
Take this:
The purpose of the table is to show how KS2 levels translate to KS4 attainment. As a parent, this raises two questions:
  1. Do you actually understand what it shows (ie does the chart do the job it is deigned to)
  2. Once you understand it, does that understanding allow you to make a inference and draw a conclusion

Do you understand it?
It takes some work, but from the English part of the chart, I can deduce that the most common incoming level is Level 4 and that those with a Level 4 are most likely to go on and get a "C" grade in GCSE. I can also see that those that obtained a "B" grade, came to school most commonly with a level 5. On the left of the table is some measure of the numbers of levels of progress 3, 4 and 5. If I look closely at the numbers, I can see that the biggest number is "99" corresponding to 3 Levels of progress.
  • But - is this good or bad?
  • Is it better than other schools?
  • Does it matter to my child?

Some Excel-fu later (a bubble chart):
Bubble charts encode 3 independent pieces of information on one chart - KS2 level and KS4 results and the number of learners getting each combination. As an extra I've encoded the number of levels of progress as a colour.
It shows the same information as the table, but is much easier to digest.
But, again does it mean anything to a parent? Does it help me make a decision about the school? Was it worthy of sharing with the wider world?
Sure, it's interesting and for those in the system we can make judgements about the progress learners make but would this be more useful?

Yes, less information but to a parent it tells me the essential: "80% made 3+ levels and 93% made 2+ levels" << sometimes less is more (useful)

Call to action
  • Know your audience
  • Less is more (depending on the audience)
  • Ask yourself "Who is going to read this and what do they need to know?"