Common Chart Design Pitfalls: Appropriate Chart Ranges

Here are some guidelines to ensure that chart ranges are appropriate for the data and chart type. 

1. Understand your data: The first step in creating an effective chart is to know your data well. This means understanding the data’s values, ranges, and context. For example, if you are working with percentages, you should be aware that the maximum value possible is 100%.
2. Choose the right chart type: Depending on the data, you should be able to pick the appropriate chart type. For example, a pie chart or a 100% stacked bar/column chart would be suitable for dealing with parts of a whole. A line or area chart would be more appropriate when depicting data over time. 
3. Set appropriate chart ranges: Once you have chosen the right chart type, ensure the value axis has an appropriate range. For percentage-based charts like pie charts and 100% stacked charts, the range should naturally extend up to 100% because of the nature of the data.
4. Adjust tick marks and labels if necessary: Depending on the data and the chart type, you might want to adjust the tick marks and labels on the value axis. For instance, with a 100% stacked chart, having labels at 0%, 25%, 50%, 75%, and 100% might be more readable than having labels at every 5%. Customize these labels based on your data to make it more intuitive for your audience.
5. Avoid distortion and be mindful of scaling: When dealing with data that has large differences or small variations, it’s important to be cautious of the scaling on the value axis. A compressed scale might exaggerate the differences, while an expanded scale might make small variations appear insignificant. Consider using other chart types or additional reference lines to highlight the relevant information in such cases.