Odd One Out

Odd-one-out tasks probe rule extraction across multiple feature dimensions: shape, color, size, fill.

You must inspect all 4 items, identify which dimension is shared by 3, and which 1 differs.

Each puzzle is generated procedurally — endless variants without memorization.

Speed and accuracy together index abstract reasoning fluency.

Each test is constructed using Item Response Theory (IRT) and Classical Test Theory (CTT) to ensure reliable measurement of knowledge and ability across different difficulty levels.

Questions undergo rigorous review including difficulty calibration, discrimination analysis, and distractor effectiveness evaluation to maintain high assessment quality.

1. Four figures appear in a 2×2 grid.
2. Look across shape, color, size, and fill.
3. Click the figure that breaks the dominant pattern.
4. Faster correct = more XP.