sentence: Pie charts are rare in scientific writing.
sentences_after: They are more common in business and economics. One reason for this may be that it is more  to compare the size of items in a chart when area is used instead of length. Stevens' power law says that it is harder to see small differences using visual area than when using length. This means that length is a better scale to use, because differences can be found out easier.
concept_name: pie chart
headings: Pie chart Warning against usage