visual-encoding

Topics in the source

• Visual Encoding
• Purpose
• When to invoke
• Inputs
• Required intermediate representation
• Procedure
• Hard constraints
• Strong heuristics

Choose the visual channels that carry each data field so the reader decodes the most important quantities most accurately, without distortion. Encoding is where perceptual accuracy and quantitative honesty are won or lost. After visual-intent has produced an intent record and candidate chart families; before layout/annotation. Also when reviewing an existing chart's channel choices. The intent record (takeaway, audience, medium, data abstraction, reader task, candidate families) from visual-intent. An encoding table: 1. Rank the data fields by decision-importance. Put the most accuracy-critical field on the highest-precision channel available: position > length > angle/slope > area > color-intensity (ENC-01). 2. Choose the chart type from the candidate families that best honors that ranking; align compared items on a common scale/baseline (ENC-05). 3. Set baselines: bars and columns MUST anchor at zero (ENC-02). For line/point charts, decide baseline by ratio-vs-difference intent and surface it as an explicit choice (UNC-01, ESCALATE) — do not silently truncate. 4. Reject low-accuracy encodings where precision matters: no area/intensity for precise magnitudes (ENC-03); no pie/donut

This is an excerpt. Refer to the complete source and its current requirements.