Step 3 - Apply SHARC Framework
Choose the purpose
Choose chart type
Design principles
Purpose
/
Communicative
/
Line Chart
Communicative Line Chart
Use a communicative line chart with SHARC to navigate viewers through specific data  that has chronological change in a numeric value(s) over time.
For example, apply SHARC to highlight the details that show Italy’s BMW production has an overall increase since 2015.
Note: By including “other” data, the chart can still be exploratory for the viewers and gives the data context.
Anatomy
Title
- Be specific in naming the data you want to highlight within the dataset.
Axes labels
- Provide a label for both the  X and Y axes.
Legends
- When you’re displaying 2 or more data points, provide legends.
Apply SHARC Framework
ScaleHierarchyAxisReadabilityColor
Don'ts - Hierarchy
The title and supporting elements imply all data and details have equal weight. For communicative, state your data story and use supporting elements to create a visual path.
Do's - Hierarchy
The title clearly states a data story to follow. Guide viewers from most important to supporting details through font size and boldness and choice of colors (see Color).
Hierarchy_tag
Don'ts - Scale
The numerical value on the Y axis is inconsistent, which makes the chart confusing and possibly leads the viewer down the wrong path.
Do's - Scales
Both the numerical values along the Y axis and the years along the X axes are consistent, so the viewer easily understands the layout.
Scale_tag
Don'ts - Readability
When visual clutter and dominates the chart, viewers can spend more time trying to visually organize the clutter than interpret the data.
Do's - Readability
By clearing visual clutter, using simple, sans-serif fonts, and simple visual elements (no 3D or drop-shadows, for example). the viewer can easily focus on the data.
Readability_tag
Don'ts - Color
By having several competing colors in the chart, the viewers' attention does not follow the data story you are trying to tell.
Do's - Color
The dark blue line supports the title by highlighting BMWs production. Non-text contrast ratio of at least 3:1 is suggested for accessibility by WCAG 2.1. (See References & Resources > Accessibility & Color to learn more about color and accessibility.)
Color_tag
Don'ts - Axis
It can be misleading and difficult to understand if you do not start at zero. However, unlike bar chart, you may deviate from 'zero-rule' in case of line chart as it encodes slope/position. So, base line zero is not that important.
Do's - Axis
By labeling the X and Y axes, the chart organization is easy to understand. Line charts usually start with 0.
Axis_tag
Compare with Stacked Bar Chart
Don'ts
Use a bar chart to compare the numeric value of  2-4 different things, but not for changes over time particularly if the changes are small.
Do's
Use a line chart to emphasize chronological change in the numeric values over time. It can also be used to compare changes for multiple groups over same period of time.