Which of these is simpler?
In 1968, Christopher Alexander and Susan Carey showed Radcliffe undergraduates 35 little strips of black and white squares and asked, in four different ways, which ones were easiest to see, remember, and describe. The strips looked almost identical in complexity — each is just three black squares and four white squares in a row — yet people agreed, overwhelmingly, that some were much simpler than others. The property that best explained the difference wasn't symmetry, and it wasn't the number of blocks. It was something more specific: the number of subsymmetries — little mirror-symmetric runs of squares hidden inside the pattern.
This site lets anyone re-run the four original experiments, right now, in a browser. Every submission is saved, and the analysis on the report page recomputes itself from all the data collected so far — by you and by everyone else who has taken part. It is an experiment that never quite finishes.
Every pattern is one of the 35 possible arrangements of 3 black + 4 white squares (7!/3!4! = 35) — the exact stimulus set from the original paper.
Read the methodologyTake part
You can do one, some, or all four. Each takes 3–8 minutes. Come back anytime — more data from you strengthens the replication.
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A pattern flashes on screen. Find its twin in a scattered array of all 35, as fast as you can. Measures how quickly each pattern can be found.
Start Search → Experiment 2Subjective ordering
All 35 patterns are laid out at once. Click them in order, simplest first. Measures which patterns look simplest at a glance.
Start Ordering → Experiment 3Memorize & confuse
Study four patterns for 30 seconds, then pick them back out of a larger set. Measures which patterns are easiest to remember — and which get mistaken for others.
Start Memorizing → Experiment 4Verbal description
Describe a pattern in words for a future participant. Then try to identify a pattern from someone else's description. Measures which patterns are easiest to put into words.
Start Describing →