Overview

Charts are visual representations of data that transform numbers into graphical elements such as bars, lines, or colors.
They help users quickly understand patterns, compare values, and identify key insights that would be difficult to interpret in raw tables or datasets.

Why use charts

Charts are essential for making data understandable and actionable.
They allow users to:

  • Understand data quickly by highlighting key patterns and trends
  • Compare values and categories at a glance
  • Identify relationships and anomalies in datasets
  • Communicate insights clearly to different audiences

What makes a good chart

A good chart is not only technically correct, it is easy to understand and useful for decision-making.
The key principles are:

  • Clarity – The chart is immediately understandable
  • Context – Labels, titles, and explanations guide interpretation
  • Simplicity – The visual is not overloaded with information
  • Relevance – The data answers a real user need
  • Consistency – Design patterns are reused across charts

Poorly designed charts often fail because they:

  • Lack explanation
  • Contain too much information
  • Do not highlight a clear takeaway