Presentation, communication and dissemination of vital statistics
Another common type of chart is the line chart , which is particularly useful for showing trends in the data over time. When using this type of chart, it is important not to try to show too many lines in the same chart, because that will make it confusing and difficult to follow any one line (see an example of a chart with too many lines below).
Similarly, attention should be given to the scale on the y axis. The scale should begin at zero and if the span of the data measures shown is large the data can be converted to the natural log to fit into the chart. However, use of logs (see example below) should be considered carefully as some audiences may not be familiar with the log concept.
Finally, using coloured shading of the areas under the graph (see example below), as opposed to just coloured lines, is more effective to show differences between groups, particularly if there are more than three categories.