A ladder of seven scatter plots from r=-1 through 0 to +1.
A free, animated correlation spectrum you can read here or embed on any website, from Scrollchart.
Correlation Spectrum
The correlation spectrum arranges seven synthetic scatter plots side by side, each generated at a specific Pearson correlation coefficient: r = -1, -0.6, -0.3, 0, +0.3, +0.6, and +1. Reading from left to right, the cloud rotates from a tight downward-sloping line through shapeless scatter and then into a tight upward-sloping line. This lets readers calibrate their intuition: an r of 0.3 looks much messier than most people expect, while an r of 0.6 still carries substantial scatter even though it might be described as a moderate positive correlation.
Pearson r measures only linear association. Two variables can have r near zero and still be strongly related in a curved or non-monotonic way. The Anscombe Quartet (1973) illustrated this with four datasets that share identical summary statistics, including identical r values, but look completely different when plotted.
Correlation also says nothing about causation, and its magnitude is sensitive to outliers. A single extreme data point can drag r from near zero to 0.7 or higher in a small sample. Reading a reported correlation coefficient without seeing the scatter is always risky.
Editorial pages where a quick visual replaces a wall of text
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Source & accuracy
This correlation spectrum is an editorial illustration built to represent the concept accurately. Where it shows figures, they are typical or representative values chosen to make the relationship clear, not a single underlying dataset. The diagram and its explainer are reviewed and maintained centrally, and updated over time as understanding improves.
Seven scatter plots from perfect negative to perfect positive
A correlation spectrum displays a ladder of scatter plots spanning the full range of correlation coefficients, from r = -1 (perfect negative correlation, a descending line) through r = 0 (no correlation, a shapeless cloud) to r = +1 (perfect positive correlation, an ascending line). Each plot in the middle shows intermediate patterns. This diagram is a reference tool: it teaches viewers what different correlation strengths look like visually, making it easier to estimate correlation in real data at a glance.
Intuition and inference from visual patterns
The spectrum illustrates a key insight: correlation measures linear association only. Two variables might show a strong curved relationship (e.g., exponential growth) and still have low correlation. By seeing the same pattern repeated across seven levels, viewers develop intuition for what r = 0.5 or r = 0.8 looks like in data. Statisticians often use the spectrum in teaching to demystify correlation and to caution against over-interpreting a single r value without seeing the scatter.
Embed this diagram
Add this animated correlation spectrum to your own site. Copy one line of HTML, or use the embed builder for theme and sizing options.
Reference
What this is
A free, embeddable, animated correlation spectrum for any website.
Who uses it
Data journalists, Researchers & academics, Content marketers, News organizations.
How to embed
Copy one line of HTML. No signup. No watermark. Works in WordPress, Webflow, Ghost, Substack, plain HTML.
File size
iframe embed, ~80 KB gzipped (loads on demand, does not block your page paint).
License
Free forever. Editorial explainer text included; updated centrally over time.
Copy the universal HTML snippet, the WordPress shortcode, or an iframe fallback -
see the WordPress plugin page for details. Any format keeps
the same Core Web Vitals profile and the same explainer text.
By embedding, you acknowledge the diagram and explainer text are served from scrollchart.com and may be updated from time to time to reflect new research or to link to relevant sources within the explainer.
Frequently asked questions
Where can I get a free animated "Correlation Spectrum" for my website?
Scrollchart provides "Correlation Spectrum" as a free, embeddable animated diagram you can add to any website with one line of HTML. No signup is required and there is no watermark. The diagram and its explainer text are served from scrollchart.com, so the embed stays current without any maintenance on your end.
How do I embed a correlation spectrum in a blog post or article?
Paste the one-line HTML snippet from the Scrollchart diagram page into your post editor. It works in WordPress, Webflow, Ghost, and plain HTML with no plugin required. The animated diagram and its explainer text load from scrollchart.com and render directly in your page DOM.