 In probability theory, the sample space and the one of an experiment or random trial is the set of all possible outcomes or results of that experiment. The sample space is usually denoted using set notation, and the possible ordered outcomes are listed as elements in the set. It is common to refer to a sample space by the labels S, O, or U4 universal set. For example, if the experiment is tossing the coin, the sample space is typically the set head, tail. For tossing to coins, the corresponding sample space would be head-head-head-head-tail-tail-tail-tail commonly written H, H, height, T-H, T-D. If the sample space is unordered, it becomes head-head-head-tail-tail-tail. For tossing a single six-sided die, the typical sample space is 1, 2, 3, 4, 5, 6 and which the result of interest is the number of pips facing up. The well-defined sample space is one of three basic elements in a probabilistic model of probability space. The other two are a well-defined set of possible events of sigma algebra and a probability assigned to each event. The probability measure function.