This blog is part 1 of a ‘Tableau Analytics Pane’ series where I will be explaining the features within the Analytics Pane.
Reference Lines and Bands are a very handy way of seeing how well something is performing against a target value or range of values.
What are Reference Lines?
Reference lines are vertical or horizontal lines displayed on your view that mark a value such as average, median, minimum, maximum, sum, total and constants.
And reference bands?
Reference bands are shaded areas on a chart that highlight a range of values in the view. Similar to reference lines, they cover the area between two relevant values such as average, median, minimum and maximum.
Reference Lines and Bands in Tableau
Reference lines and bands in Tableau are easy to use and can simply be dragged on to the view from the ‘Analytics’ pane for an instant insight or can be customised depending on its purpose.
Tableau allows you to either choose a line/band that has already been configured in the ‘Summarize’ section (Constant Line, Average Line, Median with Quartiles, Average with 95% CI and Median with 95% CI)
Or you can customise it yourself by dragging the reference line or reference band from the ‘Custom’ section.
A company wants to see how something within their organisation is performing against a target.
Reference Line – Which segment has not hit the average profit goal across all regions?
Reference Band – Which months have the sales in each segment not stayed within the margin of £40,000 and £150,000?
As you can see it is easy to spot which segments are overperforming/underperforming in the year. (GOOD – Consumer in August – September & November – December | BAD – Home Office in January – May)
The above examples are just a few of the many ways that you can use the reference lines/bands feature in Tableau and below I will explain how you can modify each of these methods.
How do you configure your lines/bands?
Dragging on the ‘Custom’ line/band allows you to decide what kind of analysis you want to do with the line/band.
Reference Band configuration is very similar to that of the reference line but has an additional set of configurations for the bottom line of the band.
Entire Table – Creates a line/band based on the aggregate value of everything on the table. The above average profit line would be an example of this as Tableau has calculated the average for all segments and set that value for the whole table.
Per Pane – Same as above but instead Tableau would calculate a value based on each individual segment. Average profit line for each segment would be different.
Per Cell – Again, the same as above but this time the line would be set for each individual Region within the Segments.
Line|Band From|Band To:
Value – Allows you to select what aggregation level you would like to view (Total, Sum, Constant, Min, Max, Average or Median). You can also choose if the value for the line/band comes from the measure used or from a created parameter.
Label – Allows the user to choose what is shown on the label of the line/band. This could be a value, a user defined text or just hidden.
If you select Average or Median you will be able to choose a line with confidence intervals or just the confidence intervals only further enhancing your analysis.
This section allows you to choose how your line looks by changing its colour, thickness and style as well as letting you choose if you want to fill in the area above or below the line with a background colour.
For bands this feature lets you choose the colour of the shaded band.
Now that you have an understanding of reference lines and bands in Tableau you can go forth and play around with the settings and see how they look with your data.
In part 2 I will be covering Box Plots in Tableau.