A current examiner recently told me that the most common mistake in students' task 1 essays is that there is no overview. This was also true when I was an examiner.
So what makes a good overview? Here are a few tips:
- An overview is simply a summary of the main things you can see.
- Because the overview is so important, I recommend putting it at the beginning of your essay, just after the introduction sentence.
- I write two overview sentences. A one-sentence overview isn't really enough.
- Try not to include specific numbers in the overview. Save the specifics for later paragraphs.
- Look at the 'big picture' e.g. the overall change from the first year to the last year (if years are shown on the chart), the differences between whole categories rather than single numbers, or the total number of stages in a process.
Have another look at the overview paragraphs (paragraph 2) in the essays I've written here on the site. Analyse them carefully, and practise writing your own overviews in the same way.