Information Design: vertical axis "rubbish"
Analyzing a newscast chart
Last week Wednesday I had a look on television at the newscast “heute ” on german television (ZDF ). A contribution reported about the planned expenditures in the household of the German Federal Government for 2017 . In the introduction this chart was shown:
Screenshot of the newscast (Source: ZDF) It's a serious broadcasting Station, but something in this chart disturbed me, so I looked the video of the newscast once again in the “Mediathek” of the ZDF . It was shown only for few seconds. To be able to understand it, I have increased it:
Increased chart (Source: ZDF) Then while increasing I have understood what disturbed me: the vertical axis. This begins with 200. It is a "lie axis"! Why? Just with column charts it is necessary compelling that the vertical axis begins with 0. Only so the viewer can get an exact impression about different heights of the columns. Therefore, scaling of axis is a central point of the IBCS rules and a Basic rule of the BI Information Design.
Eliminate the "lying" vertical axis
OK, it was important to the designer of the charts to make the increase of the expenditures clear. But: must the axis be cut off for it? If the axis begins with 0, the Chart looks thus:
Extended vertical axis (Source: ZDF) Allowedly: now the difference is not so well evident any more. But: the "relations" are straightened again.
And where it gives just so much pleasure: even other basic design rules can be applied. So we eliminate the whole "design rubbish". As first we remove the available redundancy:
Remove redundancy (Source: ZDF)
Color generates attention
In the next step we erase our "favorite" axis, the vertical axis. The values are already on the columns, therefore, the axis and the grid lines are not required. Colour generates attention . In the example orange columns on blue background are generated. Though this is very full of contrast, indeed, the attention is not drawn to the most important number: the increase about 2,7%. With the white writing and the blue background this important number "becomes blurred" with the other elements in the chart. It makes sense to reduce first all colours to a minimum:
Without color attention (Source: ORAYLIS GmbH) The value of 2017 is a Forecast value. It is advisable to explain differently forecast-and actual values. We do this here in which we show the column for 2017 hatched:
(Source: ORAYLIS GmbH)
Transform a statistics into a report
Now we look to the headings: first we need a message. With a message we transform a simple statistics into a report. The title contains the information about what it is, which unity is used and which period is shown:
Switched into a report (Source: ORAYLIS GmbH)
Tell the whole story
Nevertheless, looks quite good. However, is this the whole story? The Federal Government rules since 2014. To judge the whole situation it makes sense to have a look at the whole legislative period. These data have been published by the Ministry of Finance .
The whole story (Source: ORAYLIS GmbH)
Visualise the message
Now we must visualise the message. We reach this with the representation of the increase in percent values. Because it is here about expenditures, the plus values are red and the minus values are shown green. With these supplements we can make the message completely: the increase has been lower towards in 2015/2016 about 0,6%.
The final result (Source: ORAYLIS GmbH) OK, maybe the design is not hip and trendy. But with the changes the attention is drawn to the essentials of charts: the values.