Line Graphs

Lecture Pod 4 – Data Presentation Styles: Why do we use graphs?


*This image was taken from the lecture.

To put it simply, this lecture was about why we use graphs. I know, it’s an exciting topic, but an important one. We use graphs to make comparisons easier. That’s why bar charts are so good. They allow simple comparisons. Bubble charts not so great at this. They only give us a general idea. Readers of a graph often simply compare the height instead of the area, making a bubble chart less powerful, despite its aesthetic appeal. We always tend to underestimate the size difference.

We also looked at three common types of graphs. First was the bar chart which is easy to use and familiar to the audience. It is often used to compare data across categories. Next was a line chart which is just as common but is better used to display trends over time.  Last were pie charts which are commonly used and misused. They are best used to show relative percentages of information.

But the most important point made here was that designers often choose how to display their data incorrectly. They don’t think about what type of data they are presenting and what would be best for it. They tend to pick their charts based on other things like aesthetics which, while important, need to be balance with actually communicating your information clearly. Designers can also be influenced by data visualisation trends at the time, which can work out terribly.


Cmielewski, L. (2016). leonGraphsPod720p. Retrieved from