Really Random vs. Seems Random

Officer Greg put together this explanation of how stratification can help your generator feel more random than random.

Humans tend to be poor estimators of randomness. […]


This is a problem for procedural generation. If your map consists of the same tile used over and over again, players (and designers) are likely to think that the algorithm is bugged. In a different strain, a map that has all the interesting features in one corner not only looks bad, but also makes for a fairly uninteresting play space. Small sample sizes selected without replacement just don’t cut it for procedural generation (and large samples are often not feasible.)

A solution is stratification. Stratification involves dividing the sampled distribution into segments (i.e. strata) and sampling randomly from each one.

The full text:

Stratification: How to Make Something Seem More Random by Making it Less So