While many random samples will be drawn using a random process, they need not be. For example, if we are antecedently convinced that the final digit of someone’s minute of birth is not correlated with their family income, we may draw a random sample of people’s incomes by choosing those whose birth minute ends in ‘7’, and that process of choice is not at all random. To be sure that our sample is random, we may wish to use random numbers to decide whether to include a given individual in the sample; to that end, large tables of random digits have been produced, displaying no order or pattern (RAND Corporation 1955). This other conception of randomness, as attaching primarily to collections of outcomes, has been termed product randomness.