Uncharted Part 4 – Less is more
We could write more about the different types of charts but we have already introduced you the most useful ones and we do not want to deprive you from the joy of discovering the rest. Therefore in the final part of this article series we would rather draw your attention to the most typical mistakes in data presentation.
Copy-pasted table
Good presentation, neat slides, then all of the sudden, on the 18th slide a blurry screenshot appears from Excel. According to the title of the slide, it shows the corporate financials but what the audience sees is just a pile of tastelessness and sloth. We all know this mistake, yet from time to time we all make it when we are in a hurry. Although data can be presented this way, the thing is that laziness can destroy all the hard work that was put into the rest of the slides. This is why we strongly recommend not to copy-paste tables from Excel. A screenshot is also not a good idea. Unless it is a four-hour-long competition, take the time and make the chart or table in PowerPoint.
Distorted data
Another common mistake is to make disproportionate charts or figures in order to dramatize data or simply because of the lack of attention. Such example is when the zero level is not at zero in a graph. This is a really bad practice as it amplifies the difference between two values and thereby misleads the audience. Another example for disproportion is when we present two objects for instance with a relative ratio of 1:2. Here we need to pay attention because – as it is illustrated in the figure below – if all sides of the smaller box was half of the length of the bigger one’s then the ratio would not be 1:2 but 1:8.
Only data
Finally we cannot forget about the ‘just to have it’-type charts and tables. They have two specific subtypes:
- “This graph looks nice, since we already worked a lot on it, let’s put it in the presentation somehow”
- “The essence would be the two numbers but I have found a bunch of interesting data related to this that can also fit on the slide,”
Of course both of them are quite dangerous. It is very important to present data that fit in the main story of the presentation and support the message of the slide. If you can explain what the slide is about with two numbers, don’t put more then. The ‘less can be more’ principle applies to data presentation as it does to presentation in general as well.*
A lot more could be told about the world of tables and graphs. But there is a point where you need to draw a line and that point is here for this article series. For those who want to know more about data presentation, I strongly recommend Gene Zelazny’s book Say It with Charts. Enjoy reading and of course: Chart up!
Disclaimer
* This does not mean of course that some important elements can be left out. Units of measurement and magnitude are often missing unfortunately causing a more difficult understanding of data.