DA0-002 Visualization and Reporting Practice Question
Which TWO are common mistakes when creating data visualizations?
⚠ Common exam trap
DA0-002 often tests whether candidates can distinguish genuine visualisation mistakes (3D distortion, truncated axes) from stylistic choices (alphabetical sorting, legends) that are perfectly valid.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Using excessive 3D effects that obscure data
Option A is correct because excessive 3D effects distort proportions and depth cues, making values harder to compare accurately and often obscuring data points behind other elements. Option E is correct because starting the y-axis at a non-zero value on a bar chart exaggerates differences between bars, misleading viewers about the true magnitude of change. Option B is not a common mistake since alphabetical sorting is a legitimate, neutral ordering choice when no natural or quantitative order exists. Option C is not a mistake because color-blind friendly palettes improve accessibility and readability. Option D is not a mistake because a legend is a standard, helpful element for identifying chart elements.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Using excessive 3D effects that obscure data
Why this is correct
Excessive 3D effects distort perception: depth, perspective and occlusion make bar heights and areas impossible to compare accurately, so viewers misread magnitudes. This directly satisfies the stem's "common mistakes" criterion, since decorative dimensionality sacrifices the precise encoding that two-dimensional position and length provide.
- ✗
Sorting categories alphabetically in a bar chart
Why it's wrong here
Alphabetical sorting is a legitimate default when categories have no inherent order, so it is not a mistake. The actual error is sorting by value when the chart's purpose is ranking, or sorting arbitrarily when a natural order exists. The option tempts because alphabetical order can obscure magnitude comparisons, but that is a design trade-off, not a common mistake.
- ✗
Choosing a color-blind friendly palette
Why it's wrong here
Colour-blind friendly palettes improve accessibility by distinguishing categories through hue, lightness and pattern rather than red-green contrast, so choosing one is good practice. The mistake is using palettes that collapse under colour-vision deficiency. The option tempts because palette selection feels like a stylistic choice, but accessibility is a correctness requirement, not an error.
- ✗
Including a legend to identify chart elements
Why it's wrong here
Legends are standard practice for multi-series charts, mapping colours or symbols to categories, so including one is not a mistake. Omitting a legend forces readers to guess which series is which, which is the actual error. The option is tempting because cluttered or redundant legends do harm, but the requirement here is identifying common mistakes, and a legend is not one.
- ✓
Starting the y-axis at a value other than zero
Why this is correct
Truncating the y-axis exaggerates differences between categories, misleading viewers about the true magnitude of variation. This is a recognised visualisation mistake because the axis scale no longer represents values proportionally from a true zero baseline.
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Last reviewed September 2026 · checked against the official CompTIA exam blueprint
This DA0-002 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the DA0-002 exam.