Random covering designs
The probability for a randomly chosen family \(\mathcal B\) of \(k\)-subsets of an \(n\)-set to cover every \(t\)-subset at least once \((n\geq k>t\geq 2)\) is shown to converge to 0 or 1 according to a certain threshold value for the cardinality of \(\mathcal B\).
scientific article; zbMATH DE number 909615