Composing Pages with Charts
Guidelines
- The essential question in data analysis is: "Compared to what"? To understand your data, you need to place it in a context.
- Most interesting problems are essentially multivariate: there are a variety of factors that interact. Include many dimensions of data in your analysis.
- "Follow your data" when you are analyzing by changing the display, the data, or the charts to show you new relationships as you try to understand what you are seeing.
- A design strategy that is often effective is: "Overview first, zoom and filter, then details-on-demand" (HCIL). Provide an overall chart that covers the problem space. You should try to use a multidimensional chart for the overview (e.g., scatter plot, Multiscape, ParaBox, Data Constellations, Map, Time Table). Use filtering and zooming to focus on a subset, then explore that subset by examining its details.
When you are designing a visual display of your data, consider these factors:
- Show as much data as you can: a chart can comfortably accommodate one to two orders of magnitude more data than a spreadsheet can.
- Extract data at the granularity of items that you want to understand. For example, if the raw data is transactions, aggregate to higher level entities (e.g., products, people, relationships).
- First choose charts that directly reflect relationships you are interested in:
- Characteristics of a field: Bar, Pie, Line Chart, Histogram
- Interaction of two things: Scatter Plot, Multiscape
- Subsets over multiple fields: ParaBox
- Outliers over multiple fields: ParaBox
- Interactions between multiple fields: Data Sheet, ParaBox
- Relationships: Data Constellations
- Events over time: Time Table
- Geospatial data: Maps
- Details about data or subsets (often used for the "details on demand"): Data Sheet
- Increase the dimensionality of your analysis by combining multiple charts into a page. Selection and coloring increase the number of dimensions that can be correlated. Filtering provides drill down to focus on a subset. (See Visual Discovery for more details.)
Too many Charts on a Page?
Here are things to try if you find your Page to be unable to fit all of the charts you think you need:
- Reexamine objective of the Page:
- What questions/problems is it trying to address?
- Are all charts needed in that Page?
- Are there other Visuals that might be as good (or better) with less space usage?
- Use multiple Pages
- Use Data Hierarchies
- Orient bars in Bar Charts sideways (except for time-related dimensions)
- Reduce font sizes (especially titles)
- Eliminate titles if redundant w/axes labels
- Align filters in two columns on left and right or along left and bottom
- Use Full Screen button (client tool only)