Dashboards rely on the power of visualization in order to let people see the message of the data to make effective decisions. How can you show the power of a dashboard when compared to a crosstab table?
In this recipe, we will see how a data visualization can have more impact than a straightforward crosstab. We will make a crosstab table in Tableau and then turn it into a data visualization to see the impact in action!
Understanding your data is an essential part of data visualization, regardless of the technology you are using. Tableau can help you to understand your data by automatically distinguishing between measures and dimensions. How do you know which are which? Look at the title of a report or dashboard. For example, if a dashboard is called Sales by Country
, then anything that comes after the by
word is a dimension and the item being counted is a measure. Dimensions and measures are explained as follows:
In this recipe, we will look at the difference between a plain table and a graphical representation of the data. While tables are data visualizations in themselves, Tableau's power lies in its ability to visualize data graphically and quickly. This recipe will demonstrate the ease of going from a table to a picture of the data. We will create a map, and the color intensity of the map coloring reflects the value.
Let's start by opening up Tableau to get ready for your first visualization.
We will need to get some data. To obtain some sample, download the Unicef Report Card spreadsheet from the following link: http://bit.ly/TableauDashboardChapter11Unicef
It will have the following columns:
The following points describe the different panels in Tableau:
The following steps can be performed to create a quick visualization:
Before
.After
.After
worksheet, look for Tableau's Show Me feature. This is a key feature of Tableau, and you can see the Show Me toolkit at the right-hand side of the Tableau interface, as shown in the following screenshot:For the purposes of this recipe, we will choose a map visualization.
After
worksheet, click on the first Measures column called Average ranking position_(for all 6 dimensions) to select it. Right-click on the column and choose Keep Only. This excludes the rest of our measures, retaining only this column. The result can be seen in the following screenshot:When we select the filled maps option, which is bordered with a heavy line at the top right-hand side row, our screen now changes to look like a filled map, in which each color corresponds to the average rank of each country. An example is shown in the following screenshot:
The Edit Colors dialog box appears. An example can be found in the next screenshot:
The Show Me toolkit takes the guesswork out of what data visualization tool to choose by offering you a selection of visualizations that are based on your data types.
The Show Me button helps you to choose which data visualization is most suited to your data. It does this using an in-built, intelligent, knowledge-based system that is part of Tableau. This helps to take the guesswork out of selecting a data visualization, which can often be a contentious issue among data consumers and business intelligence professionals alike.
Data visualization is telling a story; the value is depicted by a corresponding color intensity. This example topic involved ranking data. Therefore, the higher the number, the lower the value actually is. Here, the value refers to the country rank.
How can we make the message clearer to the users? When we visualize the data in a map, we can still use color in order to convey the message. Generally speaking, we assume that the brighter or more intense a color is, then the higher the value. In this case, we need to adapt the visualization so that the color is brighter in accordance with the rank, not the perceived integer.
Color theory is a topic in itself, and you will see practical applications as we proceed throughout this book. For further references, please see the See also section.