Study Skills > Using Data > Interpreting Data
Misleading Data
The way data is presented can mean that it either consciously or unconsciously gives the wrong impression. The major advantage of using graphs and charts to represent data is that it gives an instant visual picture of the relationship between the variables but this picture can easily be altered by using different scales and ways of presentation.
In the example below the same data on exam results is used in two different column charts.
Percentage of pupils gaining grades A-C in five academic subjects
The charts give different pictures of the performance of the pupils with Chart 2 giving the impression that results for the subjects represented by the purple and green bars are quite low. This is because a different scale has been used in Chart 2 with the scale starting at 50 and each division on the scale representing 10% rather than 20% as in Chart 1. In this example the differences in scale can be easily seen but this is not always the case so it is important to pay close attention to the scale which is used when comparing graphs.
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