Writing the category name right next to its mark removes the legend round-trip entirely

What it is

Direct labelling writes the category name beside the mark itself — at the line end, next to the point, on the slice, inside the bar — collapsing the mapping distance to zero and abolishing the chart-to-legend round-trip entirely. Reading shifts from "memorise the colour, check the key" to "read it where it is": identification completes in one step. It is the direct cure for the cost described previously and the first-choice labelling method for line charts, bars, and maps.

Why it happens

The mechanism is a change in information structure: where "colour → legend → name" was a three-step indirection, a label puts colour and name inside one fixation, turning the mapping into a single read. Working memory no longer buffers colour features, attention no longer shuttles between regions, and the label text itself joins the visual search — text can be found directly, whereas colour must be compared. The cost is not reduced; it is deleted.

Where it stops holding

Labels are not free: with many categories or dense lines they collide and need collision-avoided placement or manual nudging; cramped canvases (small screens, small multiples) may not fit them; narrow pie slices force partial labelling. So direct labelling is the default, not a universal — label where it fits, fall back to a legend where it does not, and order that legend per the next card's principle.

Applying it

• Line charts: label the series at line ends; bars: label at the bar end or inside; maps: label on the region or along a leader line.
• Set label text in body colour for contrast — a washed-out label is no label.
• Verification: produce a legend-free version and have readers name every series; a full score means labels are self-sufficient, and whatever cannot be named either gains a label or falls back to a legend for the part that will not fit.

Related

• Same group: U5.01.1 Legends force eye round-trips between chart and key · U5.01.3 Legend order should match the graphic order
• Nearby: U4.05.2 Lightness, shape, pattern, and direct labels are colour's main substitutes · U5.02.3 Above, right, and below placements carry different matching costs
• Search terms: direct labelling · line ending label · in-chart annotation