About hierarchy charts




There are two types of hierarchy chart in NVivo 11 (Update 1): tree maps and sunbursts.

In this topic


What is a hierarchy chart?

Tree map

A tree map is a diagram that shows hierarchical data as a set of nested rectangles of varying sizes. For example, use size to represent the amount of coding at each node.

Size indicates amount, for example, the number of nodes coded or amount of coding references. The tree map is scaled to best fit the available space so the sizes of the rectangles should be considered in relation to each other, rather than as an absolute number.

Larger areas display at the top left of the chart, smaller rectangles display toward the bottom right.


A sunburst is a radial tree map. Hierarchy levels are presented as rings—the innermost ring is the top level of the hierarchy. The rings are divided into segments which represent children in the hierarchy. Use this diagram to see the largest contributing segments (children) in a hierarchy of multiple levels.

When you create a hierarchy chart, it displays in Detail View with two tabs:

  • The Hierarchy Chart tab displays the visual representation of your data.

  • The Summary tab displays the underlying data in a table format.

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What can I show in a hierarchy chart?

Sources  With a hierarchy chart of sources, you can:

  • Compare the amount of coding of your sources—are some sources more heavily coded than others?

  • Identify sources with most coding references at specific nodes—for example, which sources contain the most coding references to Economy?

Nodes  With a hierarchy chart of nodes, you can:


  • Visualize prominent themes in your project

  • Identify areas that need further investigation or research

Attribute values If you have classified your sources or classified your cases, you can:

  • Check that you have consulted a variety of sources—for example, have I relied too heavily on journal articles that are more than ten years old?

  • View the demographic spread of your survey respondents

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Which type of hierarchy chart should I use?


  • Use a tree map to analyze your hierarchies in one view and compare relative sizes of different aspects of your data. It's easier to compare rectangles than curved segments, so use this chart when you want to compare lots of data and make the most use of your space. It's also easier to read the labels on this chart. Tree maps expand to take up the size of the Detail View.

  • Use the sunburst to see every level of your hierarchy and the contributing segments in each group. Use this chart when you have a deep hierarchy to visualize. It's hard to fit a circular chart into a rectangular window, so the sunburst is best used when space is not an issue. Undock Detail View and enlarge the window to see the full picture of your hierarchy and the different depths of each level. You can draw attention to a single segment or highlight a particular node.


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How display options affect the chart


By default, hierarchy charts are sized by items coded, and colored by hierarchy. Use the Size By and Color By options on the ribbon to change the way data is displayed on the chart. Refer to Change the appearance or content of a hierarchy chart for more information.

Example - Use default settings

By default, hierarchy charts are colored by Hierarchy and sized by Coding References. This means that each different parent item in the hierarchy is assigned a different color, and the child and grandchild items are lighter shades of the parent color. The items are sized by the number of items coded. This combination makes it really easy to differentiate the branches of your hierarchy.

Example - Use color and size to show the same information

This example is both sized and colored by the number of Coding References. Economy has the most coding references so it is the largest area and has the darkest color. Natural environment is smaller and has a lighter color because it has less coding references. This combination uses color and size to emphasize what you're trying to show.

Example - Use color and size to convey different information

This example is colored by Coding References and sized by Items Coded. Natural environment codes the most sources so it is the largest area and Economy has the darkest color because it has the most coding references. This combination results in an information-rich visualization, using the same chart to convey two different aspects of information about your project data.

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Understanding aggregation in a hierarchy chart


