In the previous post we looked at some of the various chart formatting options that are recommended by the Oracle Design Guidelines for reports. This included minimizing axis titles and text, and avoiding heavily colored gridlines. Following on from this, it is worth considering the placement of data labels. In order to minimize clutter in the dashboard, it is recommended that data labels be set to appear during mouseover only. The only time this should be avoided is in the case of a pie chart.
Something else to consider when setting up your Queries Views is color. Your overall dashboard will have a certain color scheme, which will usually be applied to the report as well. Therefore it is recommended that you choose a different color scheme for your charts, to ensure that they contrast sufficiently against the background colors. The Oracle Design Guidelines recommend that color schemes for charts and other objects in the reports should be set up manually, using hexadecimal code.
Line charts require a small amount of special consideration, specifically the formatting of the lines themselves. Again you wish to save space, minimize clutter but ensure that your chart is legible. Therefore the Oracle Design Guidelines recommend a default line width of ‘2’ and the symbols be switched off unless absolutely necessary. They also suggest using very bright custom colors for the lines in the chart.
As mentioned above, pie charts generally require labelling in order to be meaningful and clear. Therefore the data labels option should be set to “Always”, unless there are multiple small segments in the chart. In this case labelling each segment will cause overlapping and render the chart illegible. In cases such as this, a table or a different type of chart might be worth considering.