A clustered bar chart displays more than one data series in clustered horizontal columns. Each data series shares the same axis labels, so horizontal bars are grouped by category. Clustered bars allow the direct comparison of multiple series in a given category, but it’s more difficult for the human eye to compare the same data series across categories.
Like clustered column charts, clustered bar charts become visually complex as the number of categories or data series increase. They work best in situations where data points are limited.
Pros
- Allow direct comparison of multiple data series per category
- Can show change over time
Cons
- More difficult to compare a single series across categories
- Become visually complex as categories or series are added
Tips
- Limit data series and categories
- Avoid all 3d variants
The Pie Chart is a primary chart type in Excel. Pie charts are meant to express a “part to whole” relationship, where all pieces together represent 100%. Pie charts work best to display data with a small number of categories (2-5). For example, survey questions in yes/no format, data split by gender (male/female), new and returning visitors to a website, etc.
Pie charts should be avoided when there are many categories, or when categories do not total 100%. The human eye has trouble comparing the relative size of slices in a pie chart, so pie charts should also be avoided when slices are similar, unless similarity is the point.
Pros
- Simple, compact presentation
- Can be read “at a glance” with limited categories
- Excel can calculate % values automatically
Cons
- Difficult to compare relative size of slices
- Become cluttered and dense as categories are added
- Limited to part-to-whole data
- Poor at showing change over time
Tips
- Limit categories
- Avoid all 3d variants
