With an increase in software, there is also the option to use fancy charts to visualize data, while creating a better understanding of the underlying story. However, some charts don't work as well with time series data. The line chart is the one that works best for almost all business cases. Let's explore the case of the growth over lending in the last three years:

All of the six charts are trying to tell the same story. The bank has seen lending grow from £2.35 billion to £2.84 billion between 2015 and 2017. However, some of the charts are much better placed to tell the story. The best placed is the line chart, which depicts the time on the x-axis and the value of lending on the y-axis. As we read the chart, it becomes apparent that the line shows a growth in lending. The bar chart gives us the scale of the lending by highlighting the level of lending in the various sizes of the bars across the time. However, the bars seem like a pointless addition to the line. The area chart suffers from the same issue, where the shaded area region is an extra bit of information below the line that it depicts. In both the bar and the area chart, the shaded area doesn't add much value. The histogram confuses matters slightly, as it is a bit difficult to realize the upward trajectory of lending over the years, since the volume of lending is on the x-axis, rather than the y-axis. The scatter plot is quite similar to the line chart in the way it depicts the growth of lending. With more history to plot, we would be better off going with the line chart and having an explicit line connecting the points, rather than just seeing a scatter plot. The pie chart is the most unsuited to describe the growth in lending, as it would be a painful exercise to add up the information represented by each chart. The pie chart would have to be labeled more accurately, and even then it wouldn't be as good a representative of the data in this instance.

These six charts help to illustrate how the visualization of the data is important. The same data shown using different mediums can alter the story it conveys. As a data consumer, publisher, or analyst, it's important to be conscious of the way charts are used to visualize the data. The line chart is the best suited to convey simple growth or a decrease of numbers over a time period. Other charts do have uses when evaluating time series data. Scatter plots can help us evaluate the relationship between two variables that explain a growth in lending. We will be using scatter plots later on in the chapter to depict such relationships.