Decoding Data Visualizations
Every chart is built on a simple foundation. Before we create our own, let's master the three core building blocks of visual analytics.
Dimension (Group by)
Qualitative data that categorizes, groups, or slices your data. Think of it as the "text" or "dates".
Measure (Value)
Quantitative, numerical data that can be measured or calculated. The numbers you care about tracking.
Aggregation (Math)
How you summarize the Measure across a Dimension. You can't just plot raw numbers without summarizing them!
Knowledge Check
Identify the Dimension, Measure, and Aggregation method used for each chart.
Average Rent by Neighborhood
Total Monthly Rainfall
Service Requests by Type
Total Sales by Region & Product
Smartphone Market Share (Q3)
Maximum Temperature by City
The Seattle Data Mission
Apply your knowledge of Dimensions, Measures, and Aggregations to real-world open data.
Access the Portal
Go to the Seattle Open Data portal and open the dataset catalog.
Open Seattle Open DataPick & Visualize
Select any interesting dataset. Click the "Create Visualization" or "Visualize" button in the interface.
Build the Chart
In the visualizer pane, define your Dimension (Group by) and a Measure to render your chart.
Capture & Submit
Take a screenshot of your finished chart. Paste it into the shared Google Doc below with your analysis.
Open Google DocScreenshot Reference Guide
Windows Machine
- 1. Press Windows + Shift + S
- 2. Your screen will darken. Click and drag your mouse to select the chart area.
- 3. The image is now copied to your clipboard.
- 4. Go to the Google Doc and press Ctrl + V to paste.
Mac Machine
- 1. Press Shift + Cmd + 4
- 2. Your cursor turns into a crosshair. Click and drag to select the chart.
- 3. The image is saved to your desktop (or click the floating thumbnail to copy).
- 4. Go to the Google Doc and paste it, or drag the file directly in.