Data Storytelling: Displaying Two Dimensions

Let’s explore some popular types of two-dimensional charts, with examples for each.

  1. Scatter Plots are a fantastic way to represent the relationship between two numerical variables. Imagine you want to display the correlation between the price of a car (along the Y-axis) and its fuel efficiency (along the X-axis). Each car model would be represented as a point on the scatter plot. With all the car models plotted, it’s easier to see trends and clusters in the data. You might notice, for example, that cars with higher fuel efficiency generally cost less.

  1. Bar Charts are perfect for displaying categorical data. Let’s say you want to visualize the number of books sold by different genres. On the X-axis, you would list each genre(e.g., Science Fiction, Romance, etc.), and the height of each bar along the Y-axis would represent the number of books sold in that genre. Bar charts make it easy to read and compare values across different categories.

  1. Line Charts are ideal for visualizing the changes in a numerical value over time. For instance, you might want to plot changes in the average global temperature each year over the past century. The X-axis would represent time (e.g., in years), and the Y-axis would represent the temperature. Connecting the data points with a line makes it simple to see trends and fluctuations over time.

  1. Pie Charts are helpful for showing the proportional relationships between categories. Consider a scenario where you want to visualize the percentage breakdown of annual sales by region (e.g., North America, Europe, Asia). Each segment of the pie represents a region, and the size of the segment is proportional to the region’s percentage of total sales. Pie charts provide a quick, visual way to gauge how the different categories compare proportionally.

  1. Heat Maps provide an effective way to represent data as a grid of colored cells. For example, consider a county school system that wants to showcase which schools have the highest-performing math test scores. You could create a grid of cells corresponding to the school-test combination and color-code each cell based on its test scores. The resulting heat map would make it easy for viewers to see the county’s hottest (highest scores) and coldest (lowest scores) schools.


In summary, choosing the right two-dimensional chart depends on the type of data and the relationships you want to emphasize. Scatter plots are great for showcasing correlations between numerical variables, while bar and line charts work well for categorical data and time series data, respectively. Pie charts are ideal for displaying proportions, and heat maps visualize data using color-coded grids.

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