Earlier in the blog, we covered the basics of the Mekko or Marimekko chart. In this entry, we discuss types of analyses that are best suited for visualization through the Mekko chart. Note that not all readers will be familiar with these charts and it is important that they are well designed and simply convey the information.
The Mekko is a two dimensional stacked bar chart where the width and height of segments carry information. Unlike the bar-mekko, the Marimekko chart has a 100% y-axis.
The Marimekko is great way of answering a variety of market overview questions. For example if we want to understand who the most valuable franchises are by sport the Mekko is a succinct way of showing it (see chart below). Each column in the Mekko represents a sport and each segment is a franchise. In this example no franchise can exist in two different columns/sports. This however does not have to be true for Mekko charts in general. Often the segments in a Mekko are repeated across the columns.
Mekko chart showing most valuable franchises by sport
Other types of questions you can answer with the Marimekko include:
- How many servers do Facebook, Amazon, and Google have across the world? Here we would make each continent a column in the Mekko and each company a horizontal segment
- Who are largest medical device companies by product line? Each product line could be a column in the Mekko and each company a horizontal segment. The value plotted would be company revenue
- Which countries grow the most coffee beans in the world? The columns of the Mekko would be continents. The segments would be the countries. The value plotted would be the amount of coffee grown.
The Mekko chart is a standard option with Aploris either on your Mac or PC. Simply select the Mariekko chart option and Aploris will provide you with sample chart and template data that you can quickly modify.
Similar to the Marimekko, the Bar-mekko is a two-dimensional chart where the area of each segment is of interest. Other terms used for this type of chart include skyline chart, variable-width column graph and variwide chart. Unlike the Marimekko, the Bar-mekko does not require a 100% axis which means not all columns have to be the same height. This enables the Bar-mekko to effectively communicate two different variables.
One typical example are Bar-mekkos that show profit pools where the y-axis represents a gross or operating profit margin and the x-axis represents the revenue. In the example below, we use the Bar-mekko to examine Microsoft’s different business units (source: 2013 earnings release).
Bar-mekko or skyline chart
The reader can quickly see which units bring in the most revenue represented by the widest segments as well as which ones provide the greatest operating margin, namely the tallest segments. Since multiplying revenue and margin results in the operating income or loss, it is also easy to see which ones provide the greatest operating income by identifying the segments with largest areas.
Similar to the Marimekko, Aploris also lets users quickly create Bar-mekko charts. Users, either on Mac or PC, can toggle between Bar-mekkos and Marimekkos by turning on the 100% axis property or turning it off to switch back from Marimekko to Bar-mekko.
This posts concludes the previous post on choosing a chart type and describes the categories relationship/correlation and frequency/ranking.
A relationship between two dimensions is often displayed with a scatter chart. For instance sales growth of products can be plotted in relation to their profitability. A bubble charts adds a third dimension to the visual data. So for the sales numbers the size of each bubble could represent last year’s sales volume.
In some scenarios a correlation between two dimensions may be expected that would be visible in the scatter or bubble chart. Imagine that management realigned sales incentives to focus on the most profitable products. Hopefully, this results in a positive correlation between sales growth and product profitability. For this application some charting tools allow you to automatically insert a trend line for subsets or all data points.
Scatter chart sample: Relationship GDP/Olympic medal count
Another chart type that may be useful to relate two dimensions is a bar-mekko. Effectively, this is a column chart with variable column widths. Or a Marimekko without a 100% axis to put it another way. This could be another way display the sales data with the column width depicting revenue and its height profitability. For a limited of categories, say products in this case, this type may be easier to read than a scatter chart. At the same time it describes a composition, e.g. how the company sales are split between products.
Frequency or ranking
This category is for you if data needs to be presented for multiple items but it is not desirable or possible to combine the numbers to a composite value. A typical application would be a histogram or a distribution curve if displaying many data points. Opposed to a composition chart, median or quartile information can easily be highlighted. This again shows that it’s not primarily about the data you want to show but the point that you want to make.
If columns are ordered by their frequency values the result will be a ranking chart. Values will be displayed from highest to lowest or vice versa. To visually display which are the “top” values it may be a good idea to rotate the chart to a bar charts with the best items standing literally at the top. Of course, frequency can be substituted by any other value describing the quality of an item.