ELI5: Explain Like I'm 5

Complete spatial randomness

Complete spatial randomness means that points in a certain area are scattered around with no specific pattern in mind. Imagine you threw a handful of pebbles in a big empty room and then spread them out with your hand so that each pebble was far away from the other in a very random way. That's kind of like complete spatial randomness. Points that are close together don't form patterns; they are neither clumped together nor spread out – they are completely random.