If you are putting together charts in Tableau, understanding the fundamentals of Dimensions and Measures is important, in this blog I’ll aim to break these terms down to give you an easy understanding of what they are and the charts that best represent them.
Data is commonly represented in the form of Variables; these variables could be categorical (discrete), numeric (continuous), dates, or spatial. The easiest way to get your head around these terms is, when you think of the word categorical, think of ‘Category’ like Region, Product, or Gender. They are individually separate making them discrete and in Tableau referred to as Dimensions. The value of a categorical variable can be obtained by counting. Numeric variables, as the name indicates, are numbers, when you think of numbers, think 1 to Infinity meaning they are continuous and the value of a numeric variable can be obtained by measuring, and Tableau refers to them as Measures.
Dates however are the only variable that can be used as a Dimension or a Measure in Tableau, and Spatial data is best represented in Maps.
A chart is nothing, but a graphical representation of variables, so let’s look at some of the chart types to use based on the variables you are working with. Once you understand the basics you can experiment with the Marks in Tableau and get more creative with your visualizations. Remember, your charts must have a purpose and convey some insights. Last week for the first time I was tasked with recreating one of the Workout Wednesday challenges, I’ll highly recommend https://www.vizwiz.com/p/workout-wednesday.html to challenge yourself.
|Variable||Visual Example of Chart type|
|1 Categorial variable|
|1 Numeric variable|
|2 or more Categorical variables|
|2 Numeric variables|
|Dates and 1 or 2 Numeric variables|
The above link provides more information on Charts and is a good guide to select the correct chart to represent your data.
Now that you have an understanding of Dimensions and Measures in tableau, and created your charts, ensure that they always have;
- An appropriate Title, that’s relevant and descriptive of the insight you are trying to covey.
- Unless you are making a Sparkline, always make sure your x and y-axis start at zero.
- Appropriate use of colour, depending on your topic, avoid happy colours for sad topics and consider the colour blind.
- If you are using more than one mark size/ shape or colour, be sure to show the legend.
- Make your charts interactive through drilldowns, filters and actions.
- You are more than likely to use more than one chart in your dashboard, keep the same formatting for all of them.
- Finally, have fun!