Love Data Week

A line chart displays data points connected by a line. It's a useful kind of visualization to show trends over time, with time typically being represented along the X axis and some kind of quantity being represented along the Y axis.

You'll often see line charts for weather forecasts:

You'll also often see them representing economic data:

Yi, Mike. “A Complete Guide to Line Charts.” Chartio, https://chartio.com/learn/charts/line-chart-complete-guide/. Accessed 31 Jan. 2024.

Scatter plots are used to observe the relationship between two variables. One variable is plotted on the X axis and another value is plotted on the Y axis. Each dot represents a single item that is being measured according to both variables.

For instance, here is a scatter plot representing measurements of a sample of trees. Each dot represents a single tree, with their heights being measured along the Y axis, and their diameters being measured along the X axis:

Scatter plots can show correlations that are positive (as one variable increases, the other increases), negative (as one variable increases, the other decreases), non-linear (at different points, an increase in one variable might mean an increase or a decrease in the other variable), or null (no relationship between the two variables):

To help show correlations, a scatter plot can include a trendline:

Yi, Mike. “A Complete Guide to Scatter Plots.” Chartio, https://chartio.com/learn/charts/what-is-a-scatter-plot/. Accessed 31 Jan. 2024.

A bar chart (a.k.a. a bar graph or column chart) represents numerical measurements for a series of items. Each individual item is represented on one axis, and the measurement is represented on the other axis.

Bar charts are useful when you have a discrete number of categories that you are looking at, such as the popularity of different genres of movies:

Clustered bar charts are when you have subcategories within the categories that you are measuring, such as favorite ice cream flavor by gender:

Stacked bar charts also show subcategories, but stacked on top of one another so as to emphasize the total numbers for each category, rather than for each subcategory: 

A histogram is like a bar chart, except instead of showing a list of items on one axis and numerical values on the other axis, a histogram shows a range of numbers along one axis and numerical values on the other axis. For instance, this histogram shows how many plants a garden has with each range of heights--between 135-140cm, 140-145cm, 145-150cm, and 150-155cm:

Yi, Mike. “A Complete Guide to Bar Charts.” Chartio, https://chartio.com/learn/charts/bar-chart-complete-guide/. Accessed 31 Jan. 2024.