Atlas · skill

Data Visualization

Data visualization encodes observations and analytical results in marks, positions, scales and color so people can inspect patterns or comparisons. The competency is choosing and checking those encodings against a question, including uncertainty and data limitations, rather than treating chart production as a purely decorative reporting step.

conceptData Storytelling

What it is

A visualization maps data dimensions to perceptual properties. Position on a common scale supports comparison, while color, size and facets can distinguish additional variables. Aggregation, binning and axis transformations determine which patterns become visible and which disappear. For AI systems, charts can expose residuals, data drift, subgroup errors or pipeline failures as well as business outcomes. Visualization differs from storytelling's narrative argument and dashboards' recurring decision surface. A technically rendered chart can still be analytically wrong when its observation unit, denominator or scale is unsuitable.

What the work involves

The practitioner starts with the comparison or diagnostic question, inspects data quality and chooses a chart form that supports it. They make units and transformations explicit, select meaningful ranges and represent uncertainty or sample size where needed. They inspect the actual rendered figure and validate plotted values against the underlying calculation. Useful work produces a faithful visual artifact with enough context to interpret it, including accessible labels and a clear indication of whether the chart shows raw observations, aggregated summaries or modeled estimates.

Illustrative example

An engineer investigates rising model error after a data-pipeline change. They plot residual distributions by source and time, show sample counts and use shared ranges for comparison. A separate missingness chart reveals that one source stopped supplying a key variable. The engineer checks records behind the plotted spike and distinguishes a collection problem from a generalized deterioration of the estimator.

Limits and common mistakes

Charts can conceal small groups, missing data or dependence between observations. Color scales and axis ranges can exaggerate or suppress differences, while overplotting hides density. A pattern is not proof of a causal mechanism. Check the data transformation, perceptual comparison, uncertainty and final display conditions. Visualization should expose the evidence needed for a question; interactive controls or attractive styling cannot compensate for an unsuitable calculation.

Prerequisites

No prerequisites.

Related skills

Sources and further reading

Last updated: 2026-10-10