What's with the blue and green pills in Tableau? This question frequently arises during the first month of learning Tableau, and truly understanding why and how it works is critical to mastering It. The foundation of discrete and continuous data - and how it is visualized - represents the core building block behind developing Tableau visualizations.
Ultimately, a green vs. blue Tableau field will control how a visualization is drawn.
In this blog, we will explore why Tableau visually represents blue/green pills the way it does and how to understand its impact on effective analysis and data visualizations.
Understanding data types in Tableau is the first step to mastering this industry-leading visualization software. At its core, Tableau categorizes data into two types - discrete and continuous - with each playing a unique role in how data is visualized and interpreted.
Discrete data types are counted in distinct, separate "chunks" or categories (think of items like names or individual dates). Discrete data is about individual items that should be counted separately. Continuous data types, on the other hand, are measured across a smooth (continuous) scale and often involve numbers (such as revenue over time or temperature).
Blue represents discrete data and green represents continuous.
The distinction between discrete and continuous data is pivotal because it directly affects how you analyze and visualize data in Tableau. Choosing the right type can mean the difference between an insightful, clear visualization and a confusing one.
Discrete fields are best when you need clear, defined boundaries around data points, like categorizing customer segments. Discrete data can be sorted and organized independently. A blue discrete pill creates labels or headers within Tableau so data can be represented as individually separate and distinct.
Continuous fields shine when you want to visualize trends or changes over time, where data points are connected in a seamless flow. Continuous data often represents points in time or numerical values. A green continuous pill focuses on forming an unbroken whole by drawing an axis.
Tableau's color coding is more than just visual shorthand of the mathematical concepts of discrete and continuous data - the green vs. blue pills have a big impact on how visualizations are drawn.
Blue pills create headers for your data, dividing it into distinct blocks that are easy to compare side-by-side and sort independently. Green pills, meanwhile, generate axes, which help in creating smooth, flowing charts like line graphs or area charts. Understanding when to use each can help you design more effective and intuitive visualizations.
This is where most people new to Tableau get hung up.
A common misconception among new Tableau users is conflating dimensions with discrete (blue) data and measures with continuous (green) data. Dimensions are qualitative values that help categorize, segment, and ultimately impact the level of detail within a view. Measures are numeric, quantitative values that are aggregated within Tableau views.
With those definitions in mind, it's common to assume that blue discrete data that is drawn as labels within Tableau would always be a dimension. It's certainly the most common setup, but dimensions can also be represented on a continuous axis.
While dimensions are often discrete and measures are often continuous, this isn’t a hard and fast rule. Dimensions can be used as continuous data points, and measures can be treated discretely. This flexibility allows for more nuanced data analysis and visualization strategies, adapting to the specific needs of your dataset and analysis goals.
You can right-click on dimensions and measures within Tableau to switch their properties between discrete and continuous - and ultimately change how the visualization is drawn.
Grasping the differences between discrete and continuous data, and how Tableau represents these with blue and green pills, is crucial for anyone looking to master creating impactful and accurate visualizations within Tableau. Whether you are plotting simple bar charts or complex time series analyses, the choice between discrete and continuous can fundamentally shape your results.
Remember, the key is not just in choosing the right type of data but also in understanding why it matters for your specific visualization needs. As you become more familiar with the green vs. blue pill concepts, you'll find it easier to unlock the full potential of your data with Tableau.
To convert discrete data to continuous in Tableau, right-click on the field in the data pane or shelf and select "Convert to Continuous." Conversely, to convert continuous data to discrete, right-click on the field and choose "Convert to Discrete." This toggles the field's treatment in visualizations and analyses.