Optimizing Data Visualization: A Practical Checklist

‍1. All Visuals: Essential Guidelines

Descriptive Titles
Every chart should have a clear, descriptive title that explains its contents. A good title sets the stage for understanding the data without needing additional context.

Axis Labels vs. Direct Labeling
Avoid redundancy. For charts with a single measure and axis, use either axis labels with gridlines or direct data labeling, but not both. This reduces visual clutter and improves readability.

Horizontal Axis Labels
Ensure axis labels are horizontal, not diagonal or vertical, to avoid confusion. If your labels are too long, switch to a bar chart instead of a column chart or adjust the axis width to 50% for better alignment.
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Neutral Background Colors
If background colors are used, they should be low saturation or neutral hues. This helps the data points stand out, making the key information clear.

Chart Titles: Low Contrast
Chart title backgrounds should be light or transparent, ensuring they don’t compete for attention with the chart content itself.

Strategic Use of Bright Colors
Reserve bright, intense colors for highlighting critical data points. Use softer colors for less important items, helping guide the viewer’s focus.
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No Jargon
Ensure that the charts are free from jargon that may confuse the intended audience. The message should be clear to everyone who views the report, regardless of their familiarity with the subject.

2. Bar Charts: Best Practices

Consistent Colors
Bar charts with a single measure should use a consistent color across all bars. If necessary, conditional formatting can be used to highlight specific data points.
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Logical Ordering
When not displaying time series data, order bar charts by ascending or descending value rather than alphabetically. This arrangement highlights key trends better than arbitrary orders.
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Start at Zero
Always ensure bar charts start at zero. This allows viewers to accurately assess the length and relative difference between bars, avoiding misleading representations.
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Clustering
Clustered bar/column charts should be grouped based on the category that is being analyzed. For example, if comparing products by sales across different quarters, cluster by quarter to allow for quarter-over-quarter comparison.

3. Pie Charts: Keep It Simple

Limit Slices
Pie charts should not have more than three slices. If you have more than three categories to display, consider switching to a different chart type for better clarity.

4. Across Visuals and Pages: Consistency is Key

Slicer Location and Formatting
If slicers are used on multiple pages, ensure they are in the same location with the same formatting. Consistency helps users easily navigate between pages.
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Textbox Title Placement
Textboxes used for page titles should be located consistently across all pages, helping maintain a clean and professional layout.
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Alignment and Spacing
Ensure visuals in a row or column are perfectly aligned. Misalignment can be visually distracting, detracting from the clarity of your data. Additionally, maintain enough whitespace between charts to define clear boundaries and avoid overcrowding.

‍No Dark Borders
Dark, intense borders on charts should be avoided. If visual separation is necessary, use very light borders to keep the focus on the data, not the chart elements.
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Purposeful Proximity
Charts placed close to each other should be done so intentionally because they are more related to each other than other charts on the page.
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Distinguishable Colors
Colors within and across visuals should be easily distinguishable from each other to avoid confusion.
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Consistent Fonts
Fonts should remain consistent throughout all visuals. Any deviations should be intentional and serve a clear purpose.
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Comparable Scales
If charts are meant to be compared, make sure the axis scales are the same or obviously different to facilitate meaningful comparisons.

5. Overall Review: Telling a Story with Data

Define a Message
‍Every report should have a defined message or objective. Ensure each chart and visual ties back to this core message, guiding the viewer to the right conclusions.
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Provide Supplemental Information
Include text explanations, contextual numbers, or links to other resources where necessary. This will help provide further context and support for your data story.
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Minimal Decorative Elements
Decorative elements should not distract from the data. Only use images, shapes, or additional design elements if they help convey important information or highlight key areas of the report.
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Intentional Highlights
Make sure that any highlighted data points are done so intentionally. The use of standout colors should guide the audience’s attention, not overwhelm them.
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Logical Chart Order
Organize charts in a logical order that supports common patterns of analysis. The report should flow naturally, leading viewers from one insight to the next.

Balanced Layout
Make sure the page layout is balanced. No side of the report should feel heavier than the other.

Highlight Key Metrics
Ensure that identified key metrics are adequately featured and stand out to the viewer.

‍Conclusion: Turning Data into Actionable Insights

By following this checklist, your data visualizations will not only look professional but also communicate insights more effectively. At Delve, we believe in empowering businesses through data-driven storytelling, and optimizing your dashboards is the first step to making smarter, more informed decisions.