Data in isolation is rarely all that useful. One of the best ways to add context and clarity when communicating with data is to show data side-by-side with other data. Here are just a few examples of data that is better together than apart.
e.g. Let me see revenue over time and cost over time together.
e.g. The count of users by region over time.
If you already have two or more saved questions you’d like to compare, and they share a dimension, they can be combined on any dashboard. Here’s how:
Add a question with a dimension like time or a category to a dashboard. In practice, these will usually be line charts or bar charts.
While in edit mode on the dashboard, hovering on the card will show a “Edit data” button. Click this button to start adding series that you want to compare to the first series..
The X and Y axis will automatically update if necessary and Metabase will create a legend using the existing card titles to help you understand which question maps to which series on the chart. Repeat this process as many times as you need.
To remove a series either uncheck the box, or click the x next to the title in the legend above the chart.
Once you have your chart looking how you’d like, hit done and your changes will be shown on the card in the dashboard. Depending on how dense your data is, at this point you might want to consider enlarging your chart to make sure the data is legible.
Metabase has less information about SQL based questions, so we cannot guarantee if they can be added reliably. You’ll see a little warning sign next to SQL questions to indicate this and when you try adding them just be aware it may not work.
If you need to compare single numbers and get a sense of how they differ, Metabase also lets you turn multiple Number charts into a bar chart. To do this, follow the same process outlined above. While editing a dashboard, click “edit data” on the Number chart of your choice and then select the other saved question(s) you’d like to see represented on the bar chart. (At Metabase, we use this to create simple funnel visualizations.)
If you’re creating a new question in the query builder, you can also view the result as a multi-series visualization. To do this you’ll need to add two dimensions to your question and use an aggregation that isn’t just “raw data.”
As an example, we might want to see which service is referring the most people to our product this month.
(In the sample dataset that ships with Metabase this would involve using the Source and Created At dimensions of the “People” table.)
To do this we’d select “Count of rows” and then add “Source and “Created At.” Then, we’d add a filter to limit the results to just this month. You can learn more about how to work with the query builder in the “Asking questions” section of the user guide.
If we switch the resulting table to a line or bar chart we can now see a multi-series visualization of how each referrer has performed for us this month.
It’s worth noting that at this time you won’t be able to add another saved question to multi-series visualizations made in this fashion. Metabase can only visualize up to 10 values of a dimension at once, so you may need to filter the values if you’re selecting a field that contains a lot of values like “State.”
Go forth and start letting your data get to know each other.
Pulses let you send out a group of saved questions on a schedule via email or Slack. Get started with Pulses.