2.7. Line Charts in Looker Studio
Line Charts vs. Time Series Charts
Line charts may appear similar to time series charts, but they have a key difference: line charts can accept any kind of dimension as their dimension, not just dates. This distinction makes them versatile but also potentially misleading.
Understanding Line Charts
Unlike time series charts, which display trends over time, line charts plot numbers for different categories and connect them together.
This connection, however, suggests continuity between the values, which may not actually exist.
For example, consider a line chart showing the number of users and revenue for two countries, the US and the UK. The chart might appear to show a downward trend, but this is merely a difference in values between the two countries, not an actual trend.
The flexibility of line charts can lead to confusion or misinterpretation. For instance, if you start with a line chart and attempt to plot values over time, the months might appear in a random order (e.g., February, January, December, May). This issue occurs because line charts do not automatically sort data values in the proper sequence.
Choosing the Right Chart Type
When you need to display data over time, use a time series chart to ensure the data is sorted and presented correctly. Reserve line charts for situations where you want to show connections or relationships between different categories, keeping in mind that the implied continuity may not always be accurate.
Line charts are useful for displaying relationships between different categories. However, it's essential to be aware of their potential pitfalls and choose the appropriate chart type for your data to avoid misinterpretation.