Guess the Correlation
This is a game for calibrating your eye to correlation. A scatterplot is drawn from a hidden correlation coefficient r; you slide a guess from −1 to 1 and lock it in, then the true r and your error are revealed. A running score tracks your average error over the round so you can see yourself improving. It is a surprisingly hard skill — most people systematically underestimate how scattered a moderate correlation looks.
Runs 100% in your browser — simulations are computed locally on your device.
Read the full guide to this tool
Notes
- Pearson’s r runs from −1 (perfect negative) through 0 (no linear relation) to +1 (perfect positive).
- The cloud looks rounder than people expect: an r of 0.5 still shows a lot of scatter.
- r only measures the strength of a straight-line relation — a strong curved pattern can still have r near zero.
- Runs 100% in your browser — simulations are computed locally on your device.
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